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Scherbakov A, Linnik T, Kukhtaruk S, Yakovlev D, Nadzeyka A, Rushforth A, Akimov A, Bayer M. Ultrafast magnetoacoustics in Galfenol nanostructures. Photoacoustics 2023; 34:100565. [PMID: 38058748 PMCID: PMC10696383 DOI: 10.1016/j.pacs.2023.100565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/23/2023] [Accepted: 10/23/2023] [Indexed: 12/08/2023]
Abstract
Phonons and magnons are prospective information carriers to substitute the transfer of charge in nanoscale communication devices. Our ability to manipulate them at the nanoscale and with ultimate speed is examined by ultrafast acoustics and femtosecond optomagnetism, which use ultrashort laser pulses for generation and detection of the corresponding coherent excitations. Ultrafast magnetoacoustics merges these research directions and focuses on the interaction of optically generated coherent phonons and magnons. In this review, we present ultrafast magnetoacoustic experiments with nanostructures based on the alloy (Fe,Ga) known as Galfenol. We demonstrate how broad we can manipulate the magnetic response on an optical excitation by controlling the spectrum of generated coherent phonons and their interaction with magnons. Resonant phonon pumping of magnons, formation of magnon polarons, driving of a magnetization wave by a guided phonon wavepacket are demonstrated. The presented experimental results have great application potential in emerging areas of modern nanoelectronics.
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Affiliation(s)
- A.V. Scherbakov
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - T.L. Linnik
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Department of Theoretical Physics, V.E. Lashkaryov Institute of Semiconductor Physics, 03028 Kyiv, Ukraine
| | - S.M. Kukhtaruk
- Department of Theoretical Physics, V.E. Lashkaryov Institute of Semiconductor Physics, 03028 Kyiv, Ukraine
| | - D.R. Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | | | - A.W. Rushforth
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - A.V. Akimov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - M. Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
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2
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Blachutzik F, Meier S, Weissner M, Schlattner S, Gori T, Ullrich H, Gaede L, Achenbach S, Möllmann H, Chitic B, Aksoy A, Nickenig G, Weferling M, Pons-Kühnemann J, Dörr O, Boeder N, Bayer M, Elsässer A, Hamm CW, Nef H. Coronary intravascular lithotripsy and rotational atherectomy for severely calcified stenosis: Results from the ROTA.shock trial. Catheter Cardiovasc Interv 2023; 102:823-833. [PMID: 37668088 DOI: 10.1002/ccd.30815] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 06/07/2023] [Accepted: 08/14/2023] [Indexed: 09/06/2023]
Abstract
BACKGROUND Severely calcified coronary lesions present a particular challenge for percutaneous coronary intervention. AIMS The aim of this randomized study was to determine whether coronary intravascular lithotripsy (IVL) is non-inferior to rotational atherectomy (RA) regarding minimal stent area (MSA). METHODS The randomized, prospective non-inferiority ROTA.shock trial enrolled 70 patients between July 2019 and November 2021. Patients were randomly (1:1) assigned to undergo either IVL or RA before percutaneous coronary intervention of severely calcified coronary lesions. Optical coherence tomography was performed at the end of the procedure for primary endpoint analysis. RESULTS The primary endpoint MSA was lower but non-inferior after IVL (mean: 6.10 mm2 , 95% confidence interval [95% CI]: 5.32-6.87 mm2 ) versus RA (6.60 mm2 , 95% CI: 5.66-7.54 mm2 ; difference in MSA: -0.50 mm2 , 95% CI: -1.52-0.52 mm2 ; non-inferiority margin: -1.60 mm2 ). Stent expansion was similar (RA: 0.83 ± 0.10 vs. IVL: 0.82 ± 0.11; p = 0.79). There were no significant differences regarding contrast media consumption (RA: 183.1 ± 68.8 vs. IVL: 163.3 ± 55.0 mL; p = 0.47), radiation dose (RA: 7269 ± 11288 vs. IVL: 5010 ± 4140 cGy cm2 ; p = 0.68), and procedure time (RA: 79.5 ± 34.5 vs. IVL: 66.0 ± 19.4 min; p = 0.18). CONCLUSION IVL is non-inferior regarding MSA and results in a similar stent expansion in a random comparison with RA. Procedure time, contrast volume, and dose-area product do not differ significantly.
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Affiliation(s)
- F Blachutzik
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
| | - S Meier
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
| | - M Weissner
- Kerckhoff-Klinik, Kardiologie, Bad Nauheim, Germany
| | - S Schlattner
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
| | - T Gori
- Kardiologie 1, Universitätsmedizin Mainz, Mainz, Germany
| | - H Ullrich
- Kardiologie 1, Universitätsmedizin Mainz, Mainz, Germany
| | - L Gaede
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - S Achenbach
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - H Möllmann
- St. Johannes-Hospital, Innere Medizin 1, Dortmund, Germany
| | - B Chitic
- St. Johannes-Hospital, Innere Medizin 1, Dortmund, Germany
| | - A Aksoy
- Medizinische Klinik 2, Universitätsklinikum Bonn, Bonn, Germany
| | - G Nickenig
- Medizinische Klinik 2, Universitätsklinikum Bonn, Bonn, Germany
| | - M Weferling
- Kerckhoff-Klinik, Kardiologie, Bad Nauheim, Germany
| | - J Pons-Kühnemann
- Institute for Medical Informatics, Justus Liebig University Giessen, Giessen, Germany
| | - O Dörr
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
- German Center for Cardiovascular Research (DZHK), Rhine-Main Partner Site, Germany
| | - N Boeder
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
| | - M Bayer
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
| | - A Elsässer
- Klinik für Innere Medizin - Kardiologie, Universitätsklinikum Oldenburg, Oldenburg, Germany
| | - C W Hamm
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
- Kerckhoff-Klinik, Kardiologie, Bad Nauheim, Germany
- German Center for Cardiovascular Research (DZHK), Rhine-Main Partner Site, Germany
| | - H Nef
- Medizinische Klinik 1, Justus Liebig Universität Giessen, Giessen, Germany
- German Center for Cardiovascular Research (DZHK), Rhine-Main Partner Site, Germany
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Unterberg M, Ehrentraut SF, Bracht T, Wolf A, Haberl H, von Busch A, Rump K, Ziehe D, Bazzi M, Thon P, Sitek B, Marcus K, Bayer M, Schork K, Eisenacher M, Ellger B, Oswald D, Wappler F, Defosse J, Henzler D, Köhler T, Zarbock A, Putensen CP, Schewe JC, Frey UH, Anft M, Babel N, Steinmann E, Brüggemann Y, Trilling M, Schlüter A, Nowak H, Adamzik M, Rahmel T, Koos B. Human cytomegalovirus seropositivity is associated with reduced patient survival during sepsis. Crit Care 2023; 27:417. [PMID: 37907989 PMCID: PMC10619294 DOI: 10.1186/s13054-023-04713-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/26/2023] [Indexed: 11/02/2023] Open
Abstract
BACKGROUND Sepsis is one of the leading causes of death. Treatment attempts targeting the immune response regularly fail in clinical trials. As HCMV latency can modulate the immune response and changes the immune cell composition, we hypothesized that HCMV serostatus affects mortality in sepsis patients. METHODS We determined the HCMV serostatus (i.e., latency) of 410 prospectively enrolled patients of the multicenter SepsisDataNet.NRW study. Patients were recruited according to the SEPSIS-3 criteria and clinical data were recorded in an observational approach. We quantified 13 cytokines at Days 1, 4, and 8 after enrollment. Proteomics data were analyzed from the plasma samples of 171 patients. RESULTS The 30-day mortality was higher in HCMV-seropositive patients than in seronegative sepsis patients (38% vs. 25%, respectively; p = 0.008; HR, 1.656; 95% CI 1.135-2.417). This effect was observed independent of age (p = 0.010; HR, 1.673; 95% CI 1.131-2.477). The predictive value on the outcome of the increased concentrations of IL-6 was present only in the seropositive cohort (30-day mortality, 63% vs. 24%; HR 3.250; 95% CI 2.075-5.090; p < 0.001) with no significant differences in serum concentrations of IL-6 between the two groups. Procalcitonin and IL-10 exhibited the same behavior and were predictive of the outcome only in HCMV-seropositive patients. CONCLUSION We suggest that the predictive value of inflammation-associated biomarkers should be re-evaluated with regard to the HCMV serostatus. Targeting HCMV latency might open a new approach to selecting suitable patients for individualized treatment in sepsis.
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Affiliation(s)
- M Unterberg
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - S F Ehrentraut
- Klinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Bonn, Bonn, Germany
| | - T Bracht
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
- Medizinisches Proteom-Center, Ruhr-University Bochum, 44801, Bochum, Germany
| | - A Wolf
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - H Haberl
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - A von Busch
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - K Rump
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - D Ziehe
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - M Bazzi
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - P Thon
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - B Sitek
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
- Medizinisches Proteom-Center, Ruhr-University Bochum, 44801, Bochum, Germany
| | - K Marcus
- Medizinisches Proteom-Center, Ruhr-University Bochum, 44801, Bochum, Germany
- Medical Proteome Analysis, Center for Proteindiagnostics (PRODI), Ruhr University Bochum, 44801, Bochum, Germany
| | - M Bayer
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
- Medizinisches Proteom-Center, Ruhr-University Bochum, 44801, Bochum, Germany
| | - K Schork
- Medizinisches Proteom-Center, Ruhr-University Bochum, 44801, Bochum, Germany
- Medical Proteome Analysis, Center for Proteindiagnostics (PRODI), Ruhr University Bochum, 44801, Bochum, Germany
| | - M Eisenacher
- Medizinisches Proteom-Center, Ruhr-University Bochum, 44801, Bochum, Germany
- Medical Proteome Analysis, Center for Proteindiagnostics (PRODI), Ruhr University Bochum, 44801, Bochum, Germany
| | - B Ellger
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Klinikum Westfalen, Dortmund, Germany
| | - D Oswald
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Klinikum Westfalen, Dortmund, Germany
| | - F Wappler
- Department of Anaesthesiology and Operative Intensive Care Medicine, University of Witten/Herdecke, Cologne Merheim Medical School, Cologne, Germany
| | - J Defosse
- Department of Anaesthesiology and Operative Intensive Care Medicine, University of Witten/Herdecke, Cologne Merheim Medical School, Cologne, Germany
| | - D Henzler
- Department of Anesthesiology, Surgical Intensive Care, Emergency and Pain Medicine, Ruhr-University Bochum, Klinikum Herford, Herford, Germany
| | - T Köhler
- Department of Anesthesiology, Surgical Intensive Care, Emergency and Pain Medicine, Ruhr-University Bochum, Klinikum Herford, Herford, Germany
- Department of Anesthesiology and Intensive Care Medicine, AMEOS-Klinikum Halberstadt, Halberstadt, Germany
| | - A Zarbock
- Klinik für Anästhesiologie, Operative Intensivmedizin und Schmerztherapie, Universitätsklinikum Münster, Münster, Germany
| | - C P Putensen
- Klinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Bonn, Bonn, Germany
| | - J C Schewe
- Klinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Bonn, Bonn, Germany
| | - U H Frey
- Marien Hospital Herne, Universitätsklinikum der Ruhr-Universität Bochum, Bochum, Germany
| | - M Anft
- Center for Translational Medicine, Medical Clinic I, Marien Hospital Herne, University Hospital of the Ruhr-University Bochum, Herne, Germany
| | - N Babel
- Center for Translational Medicine, Medical Clinic I, Marien Hospital Herne, University Hospital of the Ruhr-University Bochum, Herne, Germany
| | - E Steinmann
- Department of Molecular and Medical Virology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Y Brüggemann
- Department of Molecular and Medical Virology, Ruhr University Bochum, 44801, Bochum, Germany
| | - M Trilling
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - A Schlüter
- Knappschaft Kliniken GmbH, Recklinghausen, Germany
| | - H Nowak
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
- Center for Artficial Intelligence, Medical Informatics and Data Science, University Hospital Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - M Adamzik
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - T Rahmel
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany
| | - B Koos
- Klinik für Anästhesiologie, Intensivmedizin und Schmerztherapie, Universitätsklinikum Knappschaftskrankenhaus Bochum, Bochum, Germany.
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Kirstein E, Smirnov DS, Zhukov EA, Yakovlev DR, Kopteva NE, Dirin DN, Hordiichuk O, Kovalenko MV, Bayer M. The squeezed dark nuclear spin state in lead halide perovskites. Nat Commun 2023; 14:6683. [PMID: 37865649 PMCID: PMC10590392 DOI: 10.1038/s41467-023-42265-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/04/2023] [Indexed: 10/23/2023] Open
Abstract
Coherent many-body states are highly promising for robust quantum information processing. While far-reaching theoretical predictions have been made for various implementations, direct experimental evidence of their appealing properties can be challenging. Here, we demonstrate optical manipulation of the nuclear spin ensemble in the lead halide perovskite semiconductor FAPbBr3 (FA = formamidinium), targeting a long-postulated collective dark state that is insensitive to optical pumping after its build-up. Via optical orientation of localized hole spins we drive the nuclear many-body system into this entangled state, requiring a weak magnetic field of only a few milli-Tesla strength at cryogenic temperatures. During its fast establishment, the nuclear polarization along the optical axis remains small, while the transverse nuclear spin fluctuations are strongly reduced, corresponding to spin squeezing as evidenced by a strong violation of the generalized nuclear squeezing-inequality with ξs < 0.5. The dark state corresponds to an ~35-body entanglement between the nuclei. Dark nuclear spin states can be exploited to store quantum information benefiting from their long-lived many-body coherence and to perform quantum measurements with a precision beyond the standard limit.
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Affiliation(s)
- E Kirstein
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany.
| | - D S Smirnov
- Ioffe Institute, 194021, St. Petersburg, Russia.
| | - E A Zhukov
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
| | - D R Yakovlev
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
| | - N E Kopteva
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
| | - D N Dirin
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
| | - O Hordiichuk
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - M V Kovalenko
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Department of Advanced Materials and Surfaces, Empa - Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - M Bayer
- Experimental Physics 2, Department of Physics, TU Dortmund, 44227, Dortmund, Germany
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Kalitukha IV, Yalcin E, Ken OS, Korenev VL, Akimov IA, Harkort C, Dimitriev GS, Kudlacik D, Sapega VF, Nedelea V, Zhukov EA, Yakovlev DR, Banshchikov AG, Kaveev AK, Karczewski G, Wojtowicz T, Müller M, Bayer M. Universal magnetic proximity effect in ferromagnet-semiconductor quantum well hybrid structures. J Chem Phys 2023; 159:014702. [PMID: 37403857 DOI: 10.1063/5.0153310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/12/2023] [Indexed: 07/06/2023] Open
Abstract
Hybrid ferromagnet-semiconductor systems possess new outstanding properties, which emerge when bringing magnetic and semiconductor materials into contact. In such structures, the long-range magnetic proximity effect couples the spin systems of the ferromagnet and semiconductor on distances exceeding the carrier wave function overlap. The effect is due to the effective p-d exchange interaction of acceptor-bound holes in the quantum well with d-electrons of the ferromagnet. This indirect interaction is established via the phononic Stark effect mediated by the chiral phonons. Here, we demonstrate that the long-range magnetic proximity effect is universal and observed in hybrid structures with diverse magnetic components and potential barriers of various thicknesses and compositions. We study hybrid structures consisting of a semimetal (magnetite Fe3O4) or dielectric (spinel NiFe2O4) ferromagnet and a CdTe quantum well separated by a nonmagnetic (Cd,Mg)Te barrier. The proximity effect is manifested in the circular polarization of the photoluminescence corresponding to the recombination of photoexcited electrons with holes bound to shallow acceptors in the quantum well induced by magnetite or spinel itself, in contrast to interface ferromagnet in case of metal-based hybrid systems. A nontrivial dynamics of the proximity effect is observed in the studied structures due to recombination-induced dynamic polarization of electrons in the quantum well. It enables the determination of the exchange constant Δexch ≈ 70 μeV in a magnetite-based structure. The universal origin of the long-range exchange interaction along with the possibility of its electrical control offers prospects for the development of low-voltage spintronic devices compatible with existing solid-state electronics.
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Affiliation(s)
- I V Kalitukha
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - E Yalcin
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - O S Ken
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - V L Korenev
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - I A Akimov
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - C Harkort
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - G S Dimitriev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D Kudlacik
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - V F Sapega
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - V Nedelea
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - E A Zhukov
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - A G Banshchikov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - A K Kaveev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Saint-Petersburg Alferov University, 194021 St. Petersburg, Russia
| | - G Karczewski
- Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland
| | - T Wojtowicz
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland
| | - M Müller
- Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
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6
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Bayer M, Strauss G, Syring C, Ruiters M, Becker J, Steiner A. [Implementation of biosecurity measures by hoof trimmers in Switzerland]. SCHWEIZ ARCH TIERH 2023; 165:307-320. [PMID: 37227093 DOI: doi.org/10.17236/sat00394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
INTRODUCTION Biosecurity in livestock farming includes all measures preventing pathogen introduction onto a farm (external biosecurity) and pathogen transmission on the farm itself (internal biosecurity). An important risk factor for the dissemination of infectious diseases are specialised external persons working on numerous farms, such as professional hoof trimmers in Switzerland. In the present study, 49 hoof trimmers, participating in the Swiss claw health programme and working as professionals, were questioned regarding their biosecurity measures and observed by two veterinarians during hoof trimming in order to assess the implementation of biosecurity measures by hoof trimmers. Data were processed using a scoring system, in which points were allocated to the different working methods taking into account their assumed transmission potential for infectious diseases such as digital dermatitis (DD) and Salmonellosis. The working method, which complied with the ideal biosecurity measure, was always given a whole point, whereas less optimal working methods were only given an intermediate value or no point. The scoring system helped identify precisely the strengths and weaknesses of the hoof trimmers in terms of biosecurity. The level of implementation of biosecurity measures by hoof trimmers was overall quite low (53 %=average of the overall biosecurity scores of the 49 hoof trimmers). Hoof trimmers which attended specialised training courses tended to have a higher level of implementation of biosecurity measures. The answers given by the hoof trimmers and the observations made by the veterinarians were compared, whereby it was found that hoof trimmers generally evaluated themselves better in regard to biosecurity than veterinarians assessed them. In summary and based on the results of this study, the dissemination of pathogens, such as DD associated treponemes and salmonella is possible during hoof trimming performed by external persons working on numerous farms. Thus, future training and continuing education courses should place emphasis on biosecurity.
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Affiliation(s)
- M Bayer
- Nutztierklinik, Vetsuisse-Fakultät, Universität Bern
| | - G Strauss
- Nutztierklinik, Vetsuisse-Fakultät, Universität Bern
| | - C Syring
- Nutztierklinik, Vetsuisse-Fakultät, Universität Bern
| | - M Ruiters
- Nutztierklinik, Vetsuisse-Fakultät, Universität Bern
| | - J Becker
- Nutztierklinik, Vetsuisse-Fakultät, Universität Bern
| | - A Steiner
- Nutztierklinik, Vetsuisse-Fakultät, Universität Bern
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7
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Shamirzaev TS, Shumilin AV, Smirnov DS, Kudlacik D, Nekrasov SV, Kusrayev YG, Yakovlev DR, Bayer M. Optical Orientation of Excitons in a Longitudinal Magnetic Field in Indirect-Band-Gap (In,Al)As/AlAs Quantum Dots with Type-I Band Alignment. Nanomaterials (Basel) 2023; 13:729. [PMID: 36839097 PMCID: PMC9963670 DOI: 10.3390/nano13040729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/06/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
Exciton recombination and spin dynamics in (In,Al)As/AlAs quantum dots (QDs) with indirect band gap and type-I band alignment were studied. The negligible (less than 0.2 μeV) value of the anisotropic exchange interaction in these QDs prevents the mixing of the excitonic basis states and makes the formation of spin-polarized bright excitons possible under quasi-resonant, circularly polarized excitation. The recombination and spin dynamics of excitons are controlled by the hyperfine interaction between the electron and nuclear spins. A QD blockade by dark excitons was observed in the magnetic field, that eliminates the impact of nuclear spin fluctuations. A kinetic model which accounts for the population dynamics of the bright and dark exciton states as well as for the spin dynamics was developed to quantitatively describe the experimental data.
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Affiliation(s)
- T. S. Shamirzaev
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - A. V. Shumilin
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D. S. Smirnov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D. Kudlacik
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - S. V. Nekrasov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Yu G. Kusrayev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D. R. Yakovlev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - M. Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
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8
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Kirstein E, Kopteva NE, Yakovlev DR, Zhukov EA, Kolobkova EV, Kuznetsova MS, Belykh VV, Yugova IA, Glazov MM, Bayer M, Greilich A. Mode locking of hole spin coherences in CsPb(Cl, Br) 3 perovskite nanocrystals. Nat Commun 2023; 14:699. [PMID: 36755046 PMCID: PMC9908866 DOI: 10.1038/s41467-023-36165-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 01/19/2023] [Indexed: 02/10/2023] Open
Abstract
The spin physics of perovskite nanocrystals with confined electrons or holes is attracting increasing attention, both for fundamental studies and spintronic applications. Here, stable [Formula: see text] lead halide perovskite nanocrystals embedded in a fluorophosphate glass matrix are studied by time-resolved optical spectroscopy to unravel the coherent spin dynamics of holes and their interaction with nuclear spins of the 207Pb isotope. We demonstrate the spin mode locking effect provided by the synchronization of the Larmor precession of single hole spins in each nanocrystal in the ensemble that are excited periodically by a laser in an external magnetic field. The mode locking is enhanced by nuclei-induced frequency focusing. An ensemble spin dephasing time [Formula: see text] of a nanosecond and a single hole spin coherence time of T2 = 13 ns are measured. The developed theoretical model accounting for the mode locking and nuclear focusing for randomly oriented nanocrystals with perovskite band structure describes the experimental data very well.
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Affiliation(s)
- E. Kirstein
- grid.5675.10000 0001 0416 9637Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - N. E. Kopteva
- grid.5675.10000 0001 0416 9637Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - D. R. Yakovlev
- grid.5675.10000 0001 0416 9637Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany ,grid.4886.20000 0001 2192 9124Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia ,grid.425806.d0000 0001 0656 6476P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 119991 Moscow, Russia
| | - E. A. Zhukov
- grid.5675.10000 0001 0416 9637Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany ,grid.4886.20000 0001 2192 9124Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - E. V. Kolobkova
- grid.35915.3b0000 0001 0413 4629ITMO University, 199034 St. Petersburg, Russia ,grid.437869.70000 0004 0497 4945St. Petersburg State Institute of Technology, 190013 St. Petersburg, Russia
| | - M. S. Kuznetsova
- grid.15447.330000 0001 2289 6897Spin Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg, Russia
| | - V. V. Belykh
- grid.425806.d0000 0001 0656 6476P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 119991 Moscow, Russia
| | - I. A. Yugova
- grid.15447.330000 0001 2289 6897Spin Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg, Russia
| | - M. M. Glazov
- grid.4886.20000 0001 2192 9124Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - M. Bayer
- grid.5675.10000 0001 0416 9637Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - A. Greilich
- grid.5675.10000 0001 0416 9637Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
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9
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Kirstein E, Yakovlev DR, Glazov MM, Zhukov EA, Kudlacik D, Kalitukha IV, Sapega VF, Dimitriev GS, Semina MA, Nestoklon MO, Ivchenko EL, Kopteva NE, Dirin DN, Nazarenko O, Kovalenko MV, Baumann A, Höcker J, Dyakonov V, Bayer M. The Landé factors of electrons and holes in lead halide perovskites: universal dependence on the band gap. Nat Commun 2022; 13:3062. [PMID: 35654813 PMCID: PMC9163162 DOI: 10.1038/s41467-022-30701-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 05/12/2022] [Indexed: 11/13/2022] Open
Abstract
The Landé or g-factors of charge carriers are decisive for the spin-dependent phenomena in solids and provide also information about the underlying electronic band structure. We present a comprehensive set of experimental data for values and anisotropies of the electron and hole Landé factors in hybrid organic-inorganic (MAPbI3, MAPb(Br0.5Cl0.5)3, MAPb(Br0.05Cl0.95)3, FAPbBr3, FA0.9Cs0.1PbI2.8Br0.2, MA=methylammonium and FA=formamidinium) and all-inorganic (CsPbBr3) lead halide perovskites, determined by pump-probe Kerr rotation and spin-flip Raman scattering in magnetic fields up to 10 T at cryogenic temperatures. Further, we use first-principles density functional theory (DFT) calculations in combination with tight-binding and k ⋅ p approaches to calculate microscopically the Landé factors. The results demonstrate their universal dependence on the band gap energy across the different perovskite material classes, which can be summarized in a universal semi-phenomenological expression, in good agreement with experiment. The Landé factors govern all the spin-related basic phenomena and are the key parameters which guide spintronics applications. Here, Kirstein et al. demonstrate a universal dependence of the Landé factors on the bandgap energy of several perovskite materials.
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Affiliation(s)
- E Kirstein
- Experimentelle Physik 2, Technische Universität Dortmund, 44227, Dortmund, Germany.
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44227, Dortmund, Germany. .,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia.
| | - M M Glazov
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - E A Zhukov
- Experimentelle Physik 2, Technische Universität Dortmund, 44227, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - D Kudlacik
- Experimentelle Physik 2, Technische Universität Dortmund, 44227, Dortmund, Germany
| | - I V Kalitukha
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - V F Sapega
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - G S Dimitriev
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - M A Semina
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - M O Nestoklon
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - E L Ivchenko
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - N E Kopteva
- Experimentelle Physik 2, Technische Universität Dortmund, 44227, Dortmund, Germany
| | - D N Dirin
- Department of Chemistry and Applied Biosciences, Laboratory of Inorganic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - O Nazarenko
- Department of Chemistry and Applied Biosciences, Laboratory of Inorganic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - M V Kovalenko
- Department of Chemistry and Applied Biosciences, Laboratory of Inorganic Chemistry, ETH Zürich, 8093, Zürich, Switzerland.,Department of Advanced Materials and Surfaces, Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, 8600, Dübendorf, Switzerland
| | - A Baumann
- Experimental Physics VI, Julius-Maximilian University of Würzburg, 97074, Würzburg, Germany
| | - J Höcker
- Experimental Physics VI, Julius-Maximilian University of Würzburg, 97074, Würzburg, Germany
| | - V Dyakonov
- Experimental Physics VI, Julius-Maximilian University of Würzburg, 97074, Würzburg, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44227, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
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10
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Khramova AE, Kobecki M, Akimov IA, Savochkin IV, Kozhaev MA, Shaposhnikov AN, Berzhansky VN, Zvezdin AK, Bayer M, Belotelov VI. Accumulation and control of spin waves in magnonic dielectric microresonators by a comb of ultrashort laser pulses. Sci Rep 2022; 12:7369. [PMID: 35513406 PMCID: PMC9072547 DOI: 10.1038/s41598-022-07784-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 02/14/2022] [Indexed: 11/09/2022] Open
Abstract
Spin waves in magnetic microresonators are at the core of modern magnonics. Here we demonstrate a new method of tunable excitation of different spin wave modes in magnetic microdisks by using a train of laser pulses coming at a repetition rate higher than the decay rate of spin precession. The microdisks are etched in a transparent bismuth iron garnet film and the light pulses influence the spins nonthermally through the inverse Faraday effect. The high repetition rate of the laser stimulus of 10 GHz establishes an interplay between the spin wave resonances in the frequency and momentum domains. As a result, scanning of the focused laser spot near the disk boarder changes interference pattern of the magnons and leads to a resonant dependence of the spin wave amplitude on the external magnetic field. Apart from that, we achieved a switching between volume and surface spin waves by a small variation of the external magnetic field.
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Affiliation(s)
- A E Khramova
- Russian Quantum Center, 45, Skolkovskoye shosse, Moscow, Russia, 121353. .,Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia, 119991.
| | - M Kobecki
- TU Dortmund, Experimentelle Physik 2, 44221, Dortmund, Germany
| | - I A Akimov
- TU Dortmund, Experimentelle Physik 2, 44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, St. Petersburg, Russia, 194021
| | - I V Savochkin
- Russian Quantum Center, 45, Skolkovskoye shosse, Moscow, Russia, 121353.,Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia, 119991
| | - M A Kozhaev
- Russian Quantum Center, 45, Skolkovskoye shosse, Moscow, Russia, 121353.,Prokhorov General Physics Institute RAS, 38 Vavilov Street, Moscow, Russia, 119991
| | - A N Shaposhnikov
- Vernadsky Crimean Federal University, 4 Vernadskogo Prospekt, Simferopol, Russia, 295007
| | - V N Berzhansky
- Vernadsky Crimean Federal University, 4 Vernadskogo Prospekt, Simferopol, Russia, 295007
| | - A K Zvezdin
- Russian Quantum Center, 45, Skolkovskoye shosse, Moscow, Russia, 121353.,Prokhorov General Physics Institute RAS, 38 Vavilov Street, Moscow, Russia, 119991.,NTI Center for Quantum Communications, National University of Science and Technology MISiS, Leninsky Prospekt 4, Moscow, Russia, 119049
| | - M Bayer
- TU Dortmund, Experimentelle Physik 2, 44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, St. Petersburg, Russia, 194021
| | - V I Belotelov
- Russian Quantum Center, 45, Skolkovskoye shosse, Moscow, Russia, 121353.,Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia, 119991
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11
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Smirnov DS, Shamirzaev TS, Yakovlev DR, Bayer M. Dynamic Polarization of Electron Spins Interacting with Nuclei in Semiconductor Nanostructures. Phys Rev Lett 2020; 125:156801. [PMID: 33095603 DOI: 10.1103/physrevlett.125.156801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
We suggest a new spin orientation mechanism for localized electrons: dynamic electron spin polarization provided by nuclear spin fluctuations. The detrimental effect of nuclear spin fluctuations can be harnessed and employed to provide angular momentum for the electrons via the hyperfine interaction in a weak magnetic field. For this, the sample is illuminated by an unpolarized light, which directly polarizes neither the electrons nor the nuclei. We predict that, for the electrons bound in localized excitons, 100% spin polarization can be reached in longitudinal magnetic fields of a few millitesla. The proof of principle experiment is performed on momentum-indirect excitons in (In,Al)As/AlAs quantum dots, where in a magnetic field of 17 mT the electron spin polarization of 30% is measured.
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Affiliation(s)
- D S Smirnov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - T S Shamirzaev
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Ural Federal University, 620002 Yekaterinburg, Russia
| | - D R Yakovlev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - M Bayer
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
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12
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Belykh VV, Yakovlev DR, Bayer M. Optical detection of electron spin dynamics driven by fast variations of a magnetic field: a simple method to measure [Formula: see text], [Formula: see text], and [Formula: see text] in semiconductors. Sci Rep 2020; 10:13155. [PMID: 32753635 PMCID: PMC7403391 DOI: 10.1038/s41598-020-70036-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/20/2020] [Indexed: 11/09/2022] Open
Abstract
We develop a simple method for measuring the electron spin relaxation times [Formula: see text], [Formula: see text] and [Formula: see text] in semiconductors and demonstrate its exemplary application to n-type GaAs. Using an abrupt variation of the magnetic field acting on electron spins, we detect the spin evolution by measuring the Faraday rotation of a short laser pulse. Depending on the magnetic field orientation, this allows us to measure either the longitudinal spin relaxation time [Formula: see text] or the inhomogeneous transverse spin dephasing time [Formula: see text]. In order to determine the homogeneous spin coherence time [Formula: see text], we apply a pulse of an oscillating radiofrequency (rf) field resonant with the Larmor frequency and detect the subsequent decay of the spin precession. The amplitude of the rf-driven spin precession is significantly enhanced upon additional optical pumping along the magnetic field.
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Affiliation(s)
- V. V. Belykh
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia 119991
| | - D. R. Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, St. Petersburg, Russia 194021
| | - M. Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, St. Petersburg, Russia 194021
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13
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Sortino L, Zotev PG, Mignuzzi S, Cambiasso J, Schmidt D, Genco A, Aßmann M, Bayer M, Maier SA, Sapienza R, Tartakovskii AI. Enhanced light-matter interaction in an atomically thin semiconductor coupled with dielectric nano-antennas. Nat Commun 2019; 10:5119. [PMID: 31712619 PMCID: PMC6848120 DOI: 10.1038/s41467-019-12963-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 10/07/2019] [Indexed: 11/25/2022] Open
Abstract
Unique structural and optical properties of atomically thin two-dimensional semiconducting transition metal dichalcogenides enable in principle their efficient coupling to photonic cavities having the optical mode volume close to or below the diffraction limit. Recently, it has become possible to make all-dielectric nano-cavities with reduced mode volumes and negligible non-radiative losses. Here, we realise low-loss high-refractive-index dielectric gallium phosphide (GaP) nano-antennas with small mode volumes coupled to atomic mono- and bilayers of WSe\documentclass[12pt]{minimal}
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\begin{document}$${}_{2}$$\end{document}2. We observe a photoluminescence enhancement exceeding 10\documentclass[12pt]{minimal}
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\begin{document}$${}_{2}$$\end{document}2 placed on planar GaP, and trace its origin to a combination of enhancement of the spontaneous emission rate, favourable modification of the photoluminescence directionality and enhanced optical excitation efficiency. A further effect of the coupling is observed in the photoluminescence polarisation dependence and in the Raman scattering signal enhancement exceeding 10\documentclass[12pt]{minimal}
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\begin{document}$${}^{3}$$\end{document}3. Our findings reveal dielectric nano-antennas as a promising platform for engineering light-matter coupling in two-dimensional semiconductors. Dielectric nano-antennas may be used as a platform for boosting light-matter coupling in 2D semiconductors. Here, the authors demonstrate the coupling of atomically thin WSe\documentclass[12pt]{minimal}
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\begin{document}$${}_{2}$$\end{document}2 photoluminescence enhancement.
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Affiliation(s)
- L Sortino
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK.
| | - P G Zotev
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK
| | - S Mignuzzi
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2BW, UK
| | - J Cambiasso
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2BW, UK
| | - D Schmidt
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - A Genco
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK
| | - M Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - S A Maier
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2BW, UK.,Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - R Sapienza
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2BW, UK
| | - A I Tartakovskii
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, UK.
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14
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Trifonov AV, Khramtsov ES, Kavokin KV, Ignatiev IV, Kavokin AV, Efimov YP, Eliseev SA, Shapochkin PY, Bayer M. Nanosecond Spin Coherence Time of Nonradiative Excitons in GaAs/AlGaAs Quantum Wells. Phys Rev Lett 2019; 122:147401. [PMID: 31050466 DOI: 10.1103/physrevlett.122.147401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/24/2018] [Indexed: 06/09/2023]
Abstract
We report on the experimental evidence for a nanosecond timescale spin memory based on nonradiative excitons with large in-plane wave vector. The effect manifests itself in magnetic-field-induced oscillations of the energy of the optically active (radiative) excitons. The oscillations detected by a spectrally resolved pump-probe technique applied to a GaAs/AlGaAs quantum well structure in a transverse magnetic field persist over a timescale, which is orders of magnitude longer than the characteristic decoherence time in the system. The effect is attributed to the spin-dependent electron-electron exchange interaction of the optically active and inactive excitons. The spin relaxation time of the electrons belonging to nonradiative excitons appears to be much longer than the hole spin relaxation time.
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Affiliation(s)
- A V Trifonov
- Spin Optics Laboratory, St. Petersburg State University, St. Petersburg 198504, Russia
| | - E S Khramtsov
- Spin Optics Laboratory, St. Petersburg State University, St. Petersburg 198504, Russia
| | - K V Kavokin
- Spin Optics Laboratory, St. Petersburg State University, St. Petersburg 198504, Russia
| | - I V Ignatiev
- Spin Optics Laboratory, St. Petersburg State University, St. Petersburg 198504, Russia
| | - A V Kavokin
- Spin Optics Laboratory, St. Petersburg State University, St. Petersburg 198504, Russia
- Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China and Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Y P Efimov
- Resource Center "Nanophotonics," St. Petersburg State University, St. Petersburg 198504, Russia
| | - S A Eliseev
- Resource Center "Nanophotonics," St. Petersburg State University, St. Petersburg 198504, Russia
| | - P Yu Shapochkin
- Resource Center "Nanophotonics," St. Petersburg State University, St. Petersburg 198504, Russia
| | - M Bayer
- Experimentelle Physik 2, Technische Universittat Dortmund, D-44221 Dortmund, Germany
- A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russia
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15
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Poltavtsev SV, Kapitonov YV, Yugova IA, Akimov IA, Yakovlev DR, Karczewski G, Wiater M, Wojtowicz T, Bayer M. Polarimetry of photon echo on charged and neutral excitons in semiconductor quantum wells. Sci Rep 2019; 9:5666. [PMID: 30952969 PMCID: PMC6450863 DOI: 10.1038/s41598-019-42208-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 03/01/2019] [Indexed: 11/09/2022] Open
Abstract
Coherent optical spectroscopy such as four-wave mixing and photon echo generation deliver rich information on the energy levels involved in optical transitions through the analysis of polarization of the coherent response. In semiconductors, it can be applied to distinguish between different exciton complexes, which is a highly non-trivial problem in optical spectroscopy. We develop a simple approach based on photon echo polarimetry, in which polar plots of the photon echo amplitude are measured as function of the angle φ between the linear polarizations of the two exciting pulses. The rosette-like polar plots reveal a distinct difference between the neutral and charged exciton (trion) optical transitions in semiconductor nanostructures. We demonstrate this experimentally by photon echo polarimetry of a CdTe/(Cd, Mg)Te quantum well. The echoes of the trion and donor-bound exciton are linearly polarized at the angle 2φ with respect to the first pulse polarization and their amplitudes are weakly dependent on φ. While on the exciton the photon echo is co-polarized with the second exciting pulse and its amplitude scales as cosφ.
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Affiliation(s)
- S V Poltavtsev
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.
- Spin Optics Laboratory, St. Petersburg State University, 198504, St. Petersburg, Russia.
| | - Yu V Kapitonov
- Physics Faculty, St. Petersburg State University, 199034, St. Petersburg, Russia
| | - I A Yugova
- Physics Faculty, St. Petersburg State University, 199034, St. Petersburg, Russia
| | - I A Akimov
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - G Karczewski
- Institute of Physics, Polish Academy of Sciences, PL-02668, Warsaw, Poland
| | - M Wiater
- Institute of Physics, Polish Academy of Sciences, PL-02668, Warsaw, Poland
| | - T Wojtowicz
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, PL-02668, Warsaw, Poland
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
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16
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Schmidt D, Berger B, Kahlert M, Bayer M, Schneider C, Höfling S, Sedov ES, Kavokin AV, Aßmann M. Tracking Dark Excitons with Exciton Polaritons in Semiconductor Microcavities. Phys Rev Lett 2019; 122:047403. [PMID: 30768323 DOI: 10.1103/physrevlett.122.047403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/30/2018] [Indexed: 05/13/2023]
Abstract
Dark excitons are of fundamental importance for a wide variety of processes in semiconductors but are difficult to investigate using optical techniques due to their weak interaction with light fields. We reveal and characterize dark excitons nonresonantly injected into a semiconductor microcavity structure containing InGaAs/GaAs quantum wells by a gated train of eight 100 fs pulses separated by 13 ns by monitoring their interactions with the bright lower polariton mode. We find a surprisingly long dark exciton lifetime of more than 20 ns, which is longer than the time delay between two consecutive pulses. This creates a memory effect that we clearly observe through the variation of the time-resolved transmission signal. We propose a rate equation model that provides a quantitative agreement with the experimental data.
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Affiliation(s)
- D Schmidt
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - B Berger
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Kahlert
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
- A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russia
| | - C Schneider
- Technische Physik, Universität Würzburg, 97074 Würzburg, Germany
| | - S Höfling
- Technische Physik, Universität Würzburg, 97074 Würzburg, Germany
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - E S Sedov
- School of Physics and Astronomy, University of Southampton, SO17 1NJ Southampton, United Kingdom
- Vladimir State University named after A. G. and N. G. Stoletovs, Gorky Street 87, 600000, Vladimir, Russia
| | - A V Kavokin
- Spin Optics Laboratory, St. Petersburg State University, Ulanovskaya 1, Peterhof, St. Petersburg 198504, Russia
- International Center for Polaritonics, Westlake University, No. 18, Shilongshan Road, Cloud Town, Xihu District, Hangzhou, China
| | - M Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
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17
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Bayer M, Johnstone T, Dziobek I. The impact of personal relevance on emotional face perception in adults with autism spectrum conditions - a simultaneous EEG-fMRI study. Int J Psychophysiol 2018. [DOI: 10.1016/j.ijpsycho.2018.07.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Heckötter J, Freitag M, Fröhlich D, Aßmann M, Bayer M, Grünwald P, Schöne F, Semkat D, Stolz H, Scheel S. Rydberg Excitons in the Presence of an Ultralow-Density Electron-Hole Plasma. Phys Rev Lett 2018; 121:097401. [PMID: 30230865 DOI: 10.1103/physrevlett.121.097401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/14/2017] [Indexed: 06/08/2023]
Abstract
We study the Rydberg exciton absorption of Cu_{2}O in the presence of free carriers injected by above-band-gap illumination. Already at plasma densities ρ_{EH} below one hundredth electron-hole pair per μm^{3}, exciton lines are bleached, starting from the highest observed principal quantum number, while their energies remain constant. Simultaneously, the band gap decreases by correlation effects with the plasma. An exciton line loses oscillator strength when the band gap approaches its energy, vanishing completely at the crossing point. Adapting a plasma-physics description, we describe the observations by an effective Bohr radius that increases with rising plasma density, reflecting the Coulomb interaction screening by the plasma.
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Affiliation(s)
- J Heckötter
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Freitag
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - D Fröhlich
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - P Grünwald
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
| | - F Schöne
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
| | - D Semkat
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, Felix-Hausdorff-Straße 6, D-17489 Greifswald, Germany
| | - H Stolz
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
| | - S Scheel
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
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19
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Doerr O, Walther C, Liebetrau C, Keller T, Holtkamp L, Boeder N, Bayer M, Bauer P, Moellmann H, Gaede L, Troidl C, Voss S, Bauer T, Hamm C, Nef HM. P5459MR-proANP and NT-proBNP as specific indicators of procedural success in patients with severe mitral regurgitation undergoing percutaneous mitral valve repair (MitraClip). Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p5459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- O Doerr
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
| | - C Walther
- Kerckhoff Clinic, Department of Cardiology, Bad Nauheim, Germany
| | - C Liebetrau
- Kerckhoff Clinic, Department of Cardiology, Bad Nauheim, Germany
| | - T Keller
- Kerckhoff Clinic, Department of Cardiology, Bad Nauheim, Germany
| | - L Holtkamp
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
| | - N Boeder
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
| | - M Bayer
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
| | - P Bauer
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
| | | | - L Gaede
- St. Johannes Hospital, Dortmund, Germany
| | - C Troidl
- Franz-Groedel Institute of the Kerckhoff Clinic Heart & Thorax Center, Bad Nauheim, Germany
| | - S Voss
- Franz-Groedel Institute of the Kerckhoff Clinic Heart & Thorax Center, Bad Nauheim, Germany
| | - T Bauer
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
| | - C Hamm
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
| | - H M Nef
- Justus-Liebig University Giessen, Medical Clinic I, Cardiology, Giessen, Germany
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20
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Abstract
Here we analyzed associations between muscles mass, total bone mineral content (BMC), lumbar spine bone density (BMD L1-L4) and serum or urine hormones in healthy peripubertal girls. Total BMC and areal BMD L1-L4, muscle mass and fat were measured by dual-energy X-ray absorptiometry (DXA). Muscle force (N) was estimated by a dynamometer. Circulating estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), 25-hydroxy vitamin D, parathyroid hormone (PTH), insulin-like growth factor 1 (IGF-1), leptin, osteocalcin, bone isoenzyme of alkaline phosphatase (bALP) and total calcium and phosphorus were quantified as the nocturnal melatonin and serotonin urinary excretion. Partial correlations adjusted for height, Tanner score and physical activity confirmed positive relationships between BMC or BMD L1-L4 (Z-score) and lean mass or fat. Furthermore, positive relationship was observed between BMC or BMD L1-L4 (Z-score) and serum leptin. After adjustment for Tanner score and physical activity, positive associations were observed between lean mass and IGF-1, leptin levels or muscle force. We proved positive relationships between bone mass and serum leptin in peripubertal girls.
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Affiliation(s)
- V Cirmanova
- Institute of Endocrinology, Prague, Czech Republic.
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21
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Zhukov EA, Kirstein E, Kopteva NE, Heisterkamp F, Yugova IA, Korenev VL, Yakovlev DR, Pawlis A, Bayer M, Greilich A. Discretization of the total magnetic field by the nuclear spin bath in fluorine-doped ZnSe. Nat Commun 2018; 9:1941. [PMID: 29769536 PMCID: PMC5955946 DOI: 10.1038/s41467-018-04359-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/19/2018] [Indexed: 11/17/2022] Open
Abstract
The coherent spin dynamics of fluorine donor-bound electrons in ZnSe induced by pulsed optical excitation is studied in a perpendicular applied magnetic field. The Larmor precession frequency serves as a measure for the total magnetic field exerted onto the electron spins and, surprisingly, does not increase linearly with the applied field, but shows a step-like behavior with pronounced plateaus, given by multiples of the laser repetition rate. This discretization occurs by a feedback mechanism in which the electron spins polarize the nuclear spins, which in turn generate a local Overhauser field adjusting the total magnetic field accordingly. Varying the optical excitation power, we can control the plateaus, in agreement with our theoretical model. From this model, we trace the observed discretization to the optically induced Stark field, which causes the dynamic nuclear polarization. Understanding the electron and nuclear spin interactions is essential to the application of quantum information devices. Here the authors report a step-like electron Larmor frequency versus external magnetic field due to the discretization of the total magnetic field by the nuclear spin bath in ZnSe:F.
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Affiliation(s)
- E A Zhukov
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - E Kirstein
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany
| | - N E Kopteva
- Physical Faculty of St. Petersburg State University, 198504, St. Petersburg, Russia.,Spin Optics Laboratory, St. Petersburg State University, 198504, St. Petersburg, Russia
| | - F Heisterkamp
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.,Federal Institute for Occupational Safety and Health (BAuA), 44149, Dortmund, Germany
| | - I A Yugova
- Physical Faculty of St. Petersburg State University, 198504, St. Petersburg, Russia
| | - V L Korenev
- Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - A Pawlis
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - A Greilich
- Experimentelle Physik 2, Technische Universität Dortmund, 44221, Dortmund, Germany.
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22
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Savochkin IV, Jäckl M, Belotelov VI, Akimov IA, Kozhaev MA, Sylgacheva DA, Chernov AI, Shaposhnikov AN, Prokopov AR, Berzhansky VN, Yakovlev DR, Zvezdin AK, Bayer M. Generation of spin waves by a train of fs-laser pulses: a novel approach for tuning magnon wavelength. Sci Rep 2017; 7:5668. [PMID: 28720815 PMCID: PMC5515970 DOI: 10.1038/s41598-017-05742-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 06/01/2017] [Indexed: 11/16/2022] Open
Abstract
Currently spin waves are considered for computation and data processing as an alternative to charge currents. Generation of spin waves by ultrashort laser pulses provides several important advances with respect to conventional approaches using microwaves. In particular, focused laser spot works as a point source for spin waves and allows for directional control of spin waves and switching between their different types. For further progress in this direction it is important to manipulate with the spectrum of the optically generated spin waves. Here we tackle this problem by launching spin waves by a sequence of femtosecond laser pulses with pulse interval much shorter than the relaxation time of the magnetization oscillations. This leads to the cumulative phenomenon and allows us to generate magnons in a specific narrow range of wavenumbers. The wavelength of spin waves can be tuned from 15 μm to hundreds of microns by sweeping the external magnetic field by only 10 Oe or by slight variation of the pulse repetition rate. Our findings expand the capabilities of the optical spin pump-probe technique and provide a new method for the spin wave generation and control.
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Affiliation(s)
- I V Savochkin
- Lomonosov Moscow State University, 119991, Moscow, Russia.,Russian Quantum Center, Skolkovo, 143025, Moscow, Russia
| | - M Jäckl
- Experimentelle Physik 2, TU Dortmund, D-44221, Dortmund, Germany
| | - V I Belotelov
- Lomonosov Moscow State University, 119991, Moscow, Russia. .,Russian Quantum Center, Skolkovo, 143025, Moscow, Russia.
| | - I A Akimov
- Experimentelle Physik 2, TU Dortmund, D-44221, Dortmund, Germany. .,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia.
| | - M A Kozhaev
- Russian Quantum Center, Skolkovo, 143025, Moscow, Russia.,Prokhorov General Physics Institute, Russian Academy of Sciences, 119991, Moscow, Russia
| | - D A Sylgacheva
- Lomonosov Moscow State University, 119991, Moscow, Russia.,Russian Quantum Center, Skolkovo, 143025, Moscow, Russia
| | - A I Chernov
- Russian Quantum Center, Skolkovo, 143025, Moscow, Russia.,Prokhorov General Physics Institute, Russian Academy of Sciences, 119991, Moscow, Russia
| | - A N Shaposhnikov
- Vernadsky Crimean Federal University, Vernadsky Ave. 4, 295007, Simferopol, Russia
| | - A R Prokopov
- Vernadsky Crimean Federal University, Vernadsky Ave. 4, 295007, Simferopol, Russia
| | - V N Berzhansky
- Vernadsky Crimean Federal University, Vernadsky Ave. 4, 295007, Simferopol, Russia
| | - D R Yakovlev
- Experimentelle Physik 2, TU Dortmund, D-44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
| | - A K Zvezdin
- Prokhorov General Physics Institute, Russian Academy of Sciences, 119991, Moscow, Russia.,Faculty of Physics, National Research University Higher School of Economics, Myasnitskaya 20, Moscow, 101000, Russia
| | - M Bayer
- Experimentelle Physik 2, TU Dortmund, D-44221, Dortmund, Germany.,Ioffe Institute, Russian Academy of Sciences, 194021, St. Petersburg, Russia
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23
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Riefer A, Weber N, Mund J, Yakovlev DR, Bayer M, Schindlmayr A, Meier C, Schmidt WG. Zn-VI quasiparticle gaps and optical spectra from many-body calculations. J Phys Condens Matter 2017; 29:215702. [PMID: 28374685 DOI: 10.1088/1361-648x/aa6b2a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The electronic band structures of hexagonal ZnO and cubic ZnS, ZnSe, and ZnTe compounds are determined within hybrid-density-functional theory and quasiparticle calculations. It is found that the band-edge energies calculated on the [Formula: see text] (Zn chalcogenides) or GW (ZnO) level of theory agree well with experiment, while fully self-consistent QSGW calculations are required for the correct description of the Zn 3d bands. The quasiparticle band structures are used to calculate the linear response and second-harmonic-generation (SHG) spectra of the Zn-VI compounds. Excitonic effects in the optical absorption are accounted for within the Bethe-Salpeter approach. The calculated spectra are discussed in the context of previous experimental data and present SHG measurements for ZnO.
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Affiliation(s)
- A Riefer
- Department Physik, Universität Paderborn, 33095 Paderborn, Germany
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24
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Czerniuk T, Wigger D, Akimov AV, Schneider C, Kamp M, Höfling S, Yakovlev DR, Kuhn T, Reiter DE, Bayer M. Picosecond Control of Quantum Dot Laser Emission by Coherent Phonons. Phys Rev Lett 2017; 118:133901. [PMID: 28409974 DOI: 10.1103/physrevlett.118.133901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Indexed: 06/07/2023]
Abstract
A picosecond acoustic pulse can be used to control the lasing emission from semiconductor nanostructures by shifting their electronic transitions. When the active medium, here an ensemble of (In,Ga)As quantum dots, is shifted into or out of resonance with the cavity mode, a large enhancement or suppression of the lasing emission can dynamically be achieved. Most interesting, even in the case when gain medium and cavity mode are in resonance, we observe an enhancement of the lasing due to shaking by coherent phonons. In order to understand the interactions of the nonlinearly coupled photon-exciton-phonon subsystems, we develop a semiclassical model and find an excellent agreement between theory and experiment.
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Affiliation(s)
- T Czerniuk
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - D Wigger
- Institut für Festkörpertheorie, Universität Münster, 48149 Münster, Germany
| | - A V Akimov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - C Schneider
- Technische Physik, Universität Würzburg, 97074 Würzburg, Germany
| | - M Kamp
- Technische Physik, Universität Würzburg, 97074 Würzburg, Germany
| | - S Höfling
- Technische Physik, Universität Würzburg, 97074 Würzburg, Germany
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - T Kuhn
- Institut für Festkörpertheorie, Universität Münster, 48149 Münster, Germany
| | - D E Reiter
- Institut für Festkörpertheorie, Universität Münster, 48149 Münster, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
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25
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Tiemeyer S, Bombeck M, Göhring H, Paulus M, Sternemann C, Nase J, Wirkert FJ, Möller J, Büning T, Seeck OH, Reuter D, Wieck AD, Bayer M, Tolan M. Polaron-induced lattice distortion of (In,Ga)As/GaAs quantum dots by optically excited carriers. Nanotechnology 2016; 27:425702. [PMID: 27622774 DOI: 10.1088/0957-4484/27/42/425702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report on a high resolution x-ray diffraction study unveiling the effect of carriers optically injected into (In,Ga)As quantum dots on the surrounding GaAs crystal matrix. We find a tetragonal lattice expansion with enhanced elongation along the [001] crystal axis that is superimposed on an isotropic lattice extension. The isotropic contribution arises from excitation induced lattice heating as confirmed by temperature dependent reference studies. The tetragonal expansion on the femtometer scale is tentatively attributed to polaron formation by carriers trapped in the quantum dots.
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Affiliation(s)
- S Tiemeyer
- Fakultät Physik / DELTA, Technische Universität Dortmund, D-44221 Dortmund, Germany
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26
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Grünwald P, Aßmann M, Heckötter J, Fröhlich D, Bayer M, Stolz H, Scheel S. Signatures of Quantum Coherences in Rydberg Excitons. Phys Rev Lett 2016; 117:133003. [PMID: 27715094 DOI: 10.1103/physrevlett.117.133003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Indexed: 06/06/2023]
Abstract
Coherent optical control of individual particles has been demonstrated both for atoms and semiconductor quantum dots. Here we demonstrate the emergence of quantum coherent effects in semiconductor Rydberg excitons in bulk Cu_{2}O. Because of the spectral proximity between two adjacent Rydberg exciton states, a single-frequency laser may pump both resonances with little dissipation from the detuning. As a consequence, additional resonances appear in the absorption spectrum that correspond to dressed states consisting of two Rydberg exciton levels coupled to the excitonic vacuum, forming a V-type three-level system, but driven only by one laser light source. We show that the level of pure dephasing in this system is extremely low. These observations are a crucial step towards coherently controlled quantum technologies in a bulk semiconductor.
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Affiliation(s)
- P Grünwald
- Institut für Physik, Universität Rostock, Albert-Einstein-Strasse 23, D-18059 Rostock, Germany
| | - M Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - J Heckötter
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - D Fröhlich
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - H Stolz
- Institut für Physik, Universität Rostock, Albert-Einstein-Strasse 23, D-18059 Rostock, Germany
| | - S Scheel
- Institut für Physik, Universität Rostock, Albert-Einstein-Strasse 23, D-18059 Rostock, Germany
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27
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Hackmann J, Glasenapp P, Greilich A, Bayer M, Anders FB. Influence of the Nuclear Electric Quadrupolar Interaction on the Coherence Time of Hole and Electron Spins Confined in Semiconductor Quantum Dots. Phys Rev Lett 2015; 115:207401. [PMID: 26613469 DOI: 10.1103/physrevlett.115.207401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Indexed: 06/05/2023]
Abstract
The real-time spin dynamics and the spin noise spectra are calculated for p and n-charged quantum dots within an anisotropic central spin model extended by additional nuclear electric quadrupolar interactions and augmented by experimental data. Using realistic estimates for the distribution of coupling constants including an anisotropy parameter, we show that the characteristic long time scale is of the same order for electron and hole spins strongly determined by the quadrupolar interactions even though the analytical form of the spin decay differs significantly consistent with our measurements. The low frequency part of the electron spin noise spectrum is approximately 1/3 smaller than those for hole spins as a consequence of the spectral sum rule and the different spectral shapes. This is confirmed by our experimental spectra measured on both types of quantum dot ensembles in the low power limit of the probe laser.
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Affiliation(s)
- J Hackmann
- Theoretische Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Ph Glasenapp
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - A Greilich
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - F B Anders
- Theoretische Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
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28
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Bobbs M, Frazer T, Humphrey S, Bayer M, Wilson B, Olasz E, Holland K, Johnson K, Kuzminski J. Developing a low cost, mutually beneficial teledermatology
collaboration. Ann Glob Health 2015. [DOI: 10.1016/j.aogh.2015.02.669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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29
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Zeiter B, Bayer M, Kraemer I. GM-008 Implementation of an objective structutred clinical examination and evaluation checklists at an instiute of clinical pharmacy. Eur J Hosp Pharm 2015. [DOI: 10.1136/ejhpharm-2015-000639.276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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30
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Akimov AV, Scherbakov AV, Yakovlev DR, Bayer M. Picosecond acoustics in semiconductor optoelectronic nanostructures. Ultrasonics 2015; 56:122-8. [PMID: 24650684 DOI: 10.1016/j.ultras.2014.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 02/10/2014] [Indexed: 05/07/2023]
Abstract
We overview the results of three recently performed experiments, where the picosecond acoustic technique was applied to semiconductor devices with quantum wells or quantum dots embedded in an optical microcavity. In these experiments, high amplitude picosecond strain pulses are injected into such a device and the resulting changes in the response of the optical resonance are monitored. First, in quantum well devices we observe the generation of THz sidebands in optical reflectivity near the polariton resonance. Second, for certain conditions we detect the destruction and recurrence of excitons by acoustic shock waves on picosecond time scales. Third, in a vertical cavity surface emitting laser with a quantum dot layer the injection of the picosecond strain pulses induces the giant increase of the laser output. All these effects are governed by nonadiabatic processes in the interaction between a strain pulse and the electronic quantum confined states. Their observation became possible due to the possibility of generating very short strain pulses with sufficiently high amplitude.
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Affiliation(s)
- A V Akimov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK; Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - A V Scherbakov
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia.
| | - D R Yakovlev
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia; Experimentelle Physik 2, Technische Universität Dortmund, D-44227 Dortmund, Germany
| | - M Bayer
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia; Experimentelle Physik 2, Technische Universität Dortmund, D-44227 Dortmund, Germany
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Ahad S, Hill S, Berroth R, Bayer M, Franke U, Baumbach H. Transcatheter Aortic Valve Implantation and Concomitant off Pump Revascularization - Individual Approaches. Thorac Cardiovasc Surg 2015. [DOI: 10.1055/s-0035-1544428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Glasenapp P, Sinitsyn NA, Yang L, Rickel DG, Roy D, Greilich A, Bayer M, Crooker SA. Spin noise spectroscopy beyond thermal equilibrium and linear response. Phys Rev Lett 2014; 113:156601. [PMID: 25375727 DOI: 10.1103/physrevlett.113.156601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Indexed: 06/04/2023]
Abstract
Per the fluctuation-dissipation theorem, the information obtained from spin fluctuation studies in thermal equilibrium is necessarily constrained by the system's linear response functions. However, by including weak radio frequency magnetic fields, we demonstrate that intrinsic and random spin fluctuations even in strictly unpolarized ensembles can reveal underlying patterns of correlation and coupling beyond linear response, and can be used to study nonequilibrium and even multiphoton coherent spin phenomena. We demonstrate this capability in a classical vapor of (41)K alkali atoms, where spin fluctuations alone directly reveal Rabi splittings, the formation of Mollow triplets and Autler-Townes doublets, ac Zeeman shifts, and even nonlinear multiphoton coherences.
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Affiliation(s)
- P Glasenapp
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - N A Sinitsyn
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Luyi Yang
- National High Magnetic Field Lab, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D G Rickel
- National High Magnetic Field Lab, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D Roy
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Greilich
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - S A Crooker
- National High Magnetic Field Lab, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Yang L, Glasenapp P, Greilich A, Reuter D, Wieck AD, Yakovlev DR, Bayer M, Crooker SA. Two-colour spin noise spectroscopy and fluctuation correlations reveal homogeneous linewidths within quantum-dot ensembles. Nat Commun 2014; 5:4949. [DOI: 10.1038/ncomms5949] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/09/2014] [Indexed: 11/09/2022] Open
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Berger C, Huttner U, Mootz M, Kira M, Koch SW, Tempel JS, Aßmann M, Bayer M, Mintairov AM, Merz JL. Quantum-memory effects in the emission of quantum-dot microcavities. Phys Rev Lett 2014; 113:093902. [PMID: 25215985 DOI: 10.1103/physrevlett.113.093902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Indexed: 06/03/2023]
Abstract
The experimentally measured input-output characteristics of optically pumped semiconductor microcavities exhibits unexpected oscillations modifying the fundamentally linear slope in the excitation power regime below lasing. A systematic microscopic analysis reproduces these oscillations, identifying them as a genuine quantum-memory effect, i.e., a photon-density correlation accumulated during the excitation. With the use of projected quantum measurements, it is shown that the input-output oscillations can be controlled and enhanced by an order of magnitude when the quantum fluctuations of the pump are adjusted.
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Affiliation(s)
- C Berger
- Department of Physics, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany
| | - U Huttner
- Department of Physics, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany
| | - M Mootz
- Department of Physics, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany
| | - M Kira
- Department of Physics, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany
| | - S W Koch
- Department of Physics, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany
| | - J-S Tempel
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany and Ioffe Physical-Technical Institute of the Russian Academy of Sciences, Saint Petersburg, 194021, Russia
| | - A M Mintairov
- Ioffe Physical-Technical Institute of the Russian Academy of Sciences, Saint Petersburg, 194021, Russia and Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - J L Merz
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Czerniuk T, Brüggemann C, Tepper J, Brodbeck S, Schneider C, Kamp M, Höfling S, Glavin BA, Yakovlev DR, Akimov AV, Bayer M. Lasing from active optomechanical resonators. Nat Commun 2014; 5:4038. [PMID: 25008784 PMCID: PMC4104441 DOI: 10.1038/ncomms5038] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 05/02/2014] [Indexed: 11/09/2022] Open
Abstract
Planar microcavities with distributed Bragg reflectors (DBRs) host, besides confined optical modes, also mechanical resonances due to stop bands in the phonon dispersion relation of the DBRs. These resonances have frequencies in the 10- to 100-GHz range, depending on the resonator's optical wavelength, with quality factors exceeding 1,000. The interaction of photons and phonons in such optomechanical systems can be drastically enhanced, opening a new route towards the manipulation of light. Here we implemented active semiconducting layers into the microcavity to obtain a vertical-cavity surface-emitting laser (VCSEL). Thereby, three resonant excitations--photons, phonons and electrons--can interact strongly with each other providing modulation of the VCSEL laser emission: a picosecond strain pulse injected into the VCSEL excites long-living mechanical resonances therein. As a result, modulation of the lasing intensity at frequencies up to 40 GHz is observed. From these findings, prospective applications of active optomechanical resonators integrated into nanophotonic circuits may emerge.
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Affiliation(s)
- T Czerniuk
- Experimentelle Physik 2, TU Dortmund, Dortmund 44227, Germany
| | - C Brüggemann
- Experimentelle Physik 2, TU Dortmund, Dortmund 44227, Germany
| | - J Tepper
- Experimentelle Physik 2, TU Dortmund, Dortmund 44227, Germany
| | - S Brodbeck
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Center for Complex Material Systems, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - C Schneider
- Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Center for Complex Material Systems, University of Würzburg, Am Hubland, Würzburg 97074, Germany
| | - M Kamp
- 1] Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Center for Complex Material Systems, University of Würzburg, Am Hubland, Würzburg 97074, Germany [2] School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - S Höfling
- 1] Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Center for Complex Material Systems, University of Würzburg, Am Hubland, Würzburg 97074, Germany [2] School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - B A Glavin
- V. E. Lashkaryov Institute of Semiconductor Physics, Kyiv 03028, Ukraine
| | - D R Yakovlev
- 1] Experimentelle Physik 2, TU Dortmund, Dortmund 44227, Germany [2] A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, St Petersburg 194021, Russia
| | - A V Akimov
- 1] A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, St Petersburg 194021, Russia [2] School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - M Bayer
- 1] Experimentelle Physik 2, TU Dortmund, Dortmund 44227, Germany [2] A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, St Petersburg 194021, Russia
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Bayer M, Sladovnik P, Herzog R, Kern L. Das Mounier-Kuhn-Syndrom – eine seltene Ursache rezidivierender Bronchitiden. Dtsch Med Wochenschr 2014; 139:722-5. [DOI: 10.1055/s-0034-1369903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- M. Bayer
- Medizinische Klinik, Zuger Kantonsspital, Baar
| | | | - R. Herzog
- Medizinische Klinik, Zuger Kantonsspital, Baar
| | - L. Kern
- Herz & Lungen Zentrum, Zuger Kantonsspital, Baar
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Moody G, Akimov IA, Li H, Singh R, Yakovlev DR, Karczewski G, Wiater M, Wojtowicz T, Bayer M, Cundiff ST. Coherent coupling of excitons and trions in a photoexcited CdTe/CdMgTe quantum well. Phys Rev Lett 2014; 112:097401. [PMID: 24655274 DOI: 10.1103/physrevlett.112.097401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Indexed: 06/03/2023]
Abstract
We present zero-, one-, and two-quantum two-dimensional coherent spectra of excitons and trions in a CdTe/(Cd,Mg)Te quantum well. The set of spectra provides a unique and comprehensive picture of the coherent nonlinear optical response. Distinct peaks in the spectra are manifestations of exciton-exciton and exciton-trion coherent coupling. Excellent agreement using density matrix calculations highlights the essential role of many-body effects on the coupling. Strong exciton-trion coherent interactions open up the possibility for novel conditional control schemes in coherent optoelectronics.
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Affiliation(s)
- G Moody
- JILA, University of Colorado & National Institute of Standards and Technology, Boulder, Colorado 80309-0440, USA and Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - I A Akimov
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany and A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - H Li
- JILA, University of Colorado & National Institute of Standards and Technology, Boulder, Colorado 80309-0440, USA
| | - R Singh
- JILA, University of Colorado & National Institute of Standards and Technology, Boulder, Colorado 80309-0440, USA and Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany and A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - G Karczewski
- Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland
| | - M Wiater
- Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland
| | - T Wojtowicz
- Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - S T Cundiff
- JILA, University of Colorado & National Institute of Standards and Technology, Boulder, Colorado 80309-0440, USA and Department of Physics, University of Colorado, Boulder, Colorado 80309-0390, USA
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Bayer M. Reference values of osteocalcin and procollagen type I N-propeptide plasma levels in a healthy Central European population aged 0-18 years. Osteoporos Int 2014; 25:729-36. [PMID: 23974858 DOI: 10.1007/s00198-013-2485-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 08/06/2013] [Indexed: 10/26/2022]
Abstract
UNLABELLED The aim of this study was to assess the relationships between both a marker of bone formation and a marker of bone turnover and age, sex, and pubertal stage in a group (n = 439) of healthy children and adolescents. These reference data should be instrumental in interpretation of results. INTRODUCTION The skeletal system has high metabolic activity. In children, bone markers may be useful in diagnostics and treatment management of skeletal diseases but there could be difficulties with interpretation of results. Compared with adults, children have elevated bone marker levels due to high skeletal growth velocity and rapid bone turnover. Thus, valid age- and sex-specific reference data should be obtained for each pediatric population living in a particular climate and with a similar lifestyle. The aim of this study was to assess the relationships between both a marker of bone formation (procollagen type I N-terminal propeptide [PINP]) and a marker of bone turnover (osteocalcin [OC]) and age, sex, and pubertal stage in a group of healthy children and adolescents. METHODS Four hundred thirty-nine healthy Caucasian children participated. Their height, weight, and pubertal stage were recorded. Fasting PINP and OC were measured using a morning blood sample. RESULTS The highest levels of PINP were observed during the first year of life. There is no OC postnatal peak, but levels are higher than the adult reference interval throughout childhood. OC peaks with the pubertal growth spurt at second-third Tanner stage of breast development in girls and at second-third Tanner stage of genital development in boys. PINP peaks during second-third Tanner stage of breast development in girls and at third Tanner stage of genital development in boys. CONCLUSION This study provides reference data for OC and PINP in healthy Caucasian children from a Central European population.
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Affiliation(s)
- M Bayer
- Department of Pediatrics, Faculty of Medicine in Hradec Králové, Charles University and University Hospital Hradec Králové, Sokolská 581, 500 05, Hradec Králové, Czech Republic,
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Scherbakov AV, Bombeck M, Jäger JV, Salasyuk AS, Linnik TL, Gusev VE, Yakovlev DR, Akimov AV, Bayer M. Picosecond opto-acoustic interferometry and polarimetry in high-index GaAs. Opt Express 2013; 21:16473-16485. [PMID: 23938498 DOI: 10.1364/oe.21.016473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
By means of a metal opto-acoustic transducer we generate quasi-longitudinal and quasi-transverse picosecond strain pulses in a (311)-GaAs substrate and monitor their propagation by picosecond acoustic interferometry. By probing at the sample side opposite to the transducer the signals related to the compressive and shear strain pulses can be separated in time. In addition to conventional monitoring of the reflected probe light intensity we monitor also the polarization rotation of the optical probe beam. This polarimetric technique results in improved sensitivity of detection and provides comprehensive information about the elasto-optical anisotropy. The experimental observations are in a good agreement with a theoretical analysis.
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Affiliation(s)
- A V Scherbakov
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St Petersburg, Russia.
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40
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Zapasskii VS, Greilich A, Crooker SA, Li Y, Kozlov GG, Yakovlev DR, Reuter D, Wieck AD, Bayer M. Optical spectroscopy of spin noise. Phys Rev Lett 2013; 110:176601. [PMID: 23679751 DOI: 10.1103/physrevlett.110.176601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Indexed: 06/02/2023]
Abstract
Spontaneous fluctuations of the magnetization of a spin system in thermodynamic equilibrium (spin noise) manifest themselves as noise in the Faraday rotation of probe light. We show that the correlation properties of this noise over the optical spectrum can provide clear information about the composition of the spin system that is largely inaccessible for conventional linear optics. Such optical spectroscopy of spin noise, e.g., allows us to clearly distinguish between optical transitions associated with different spin subsystems, to resolve optical transitions that are unresolvable in the usual optical spectra, to unambiguously distinguish between homogeneously and inhomogeneously broadened optical bands, and to evaluate the degree of inhomogeneous broadening. These new possibilities are illustrated by theoretical calculations and by experiments on paramagnets with different degrees of inhomogeneous broadening of optical transitions [atomic vapors of 41K and singly charged (In,Ga)As quantum dots].
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Affiliation(s)
- V S Zapasskii
- Spin Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg, Russia
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Lafrentz M, Brunne D, Kaminski B, Pavlov VV, Rodina AV, Pisarev RV, Yakovlev DR, Bakin A, Bayer M. Magneto-Stark effect of excitons as the origin of second harmonic generation in ZnO. Phys Rev Lett 2013; 110:116402. [PMID: 25166558 DOI: 10.1103/physrevlett.110.116402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Indexed: 06/03/2023]
Abstract
The magneto-Stark effect of excitons is demonstrated to be an efficient source of optical nonlinearity in hexagonal ZnO. Strong resonant second harmonic generation signals induced by an external magnetic field are observed in the spectral range of 2s and 2p excitons. The microscopic theoretical analysis shows that for excitons with a finite wave vector, exciton states of opposite parity are mixed by an effective odd parity electric field induced by the magnetic field despite its even parity. The field, spectral, and polarization dependencies of the second harmonic generation intensity validate the proposed mechanism. The observed phenomenon is not limited to a certain symmetry class and therefore must be effective in other semiconductors.
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Affiliation(s)
- M Lafrentz
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - D Brunne
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - B Kaminski
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - V V Pavlov
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - A V Rodina
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - R V Pisarev
- Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany and Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - A Bakin
- Institut für Halbleitertechnik, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
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Rose K, Penna-Martinez M, Klahold E, Kärger D, Shoghi F, Kahles H, Bayer M, Hintermann E, Pfeilschifter JM, Badenhoop K, Ramos-Lopez E, Christen U. Influence of the vitamin D plasma level and vitamin D-related genetic polymorphisms on the immune status of patients with type 1 diabetes: a pilot study. Clin Exp Immunol 2013; 171:171-85. [PMID: 23286944 DOI: 10.1111/cei.12013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2012] [Indexed: 12/14/2022] Open
Abstract
Vitamin D (VD) has been implicated in type 1 diabetes (T1D) by genetic and epidemiological studies. Individuals living in regions with low sunlight exposure have an increased T1D risk and VD supplementation reduced the risk in human individuals and mouse models. One possibility of how VD influences the pathogenesis of T1D is its immunomodulatory effect on dendritic cells (DC), which then preferentially activate regulatory T cells (T(regs) ). In the present pilot study, we collected blood samples from a small cohort of patients with T1D at baseline and months 6 and 12. VD-deficient patients were advised to supplement with 1000 IU/day VD. We found a considerable variation in the VD plasma level at baseline and follow-up. However, with higher VD plasma levels, a lower frequency of interleukin (IL)-4-producing CD8 T cells was observed. We further performed a comprehensive genotyping of 13 VD-related polymorphisms and found an association between VD plasma level and the genotype of the VD binding protein (DBP). The frequency of DC and T cell subsets was variable in patients of all subgroups and in individual patients over time. Nevertheless, we found some significant associations, including the 1,25-dihydroxyvitamin D(3) hydroxylase (CYP27B1) genotype with the frequency of DC subtypes. In summary, our preliminary results indicate only a limited influence of the VD plasma level on the immune balance in patients with T1D. Nevertheless, our pilot study provides a basis for a follow-up study with a larger cohort of patients.
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Affiliation(s)
- K Rose
- Pharmazentrum Frankfurt/ZAFES, Frankfurt am Main, Germany
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Javaux C, Mahler B, Dubertret B, Shabaev A, Rodina AV, Efros AL, Yakovlev DR, Liu F, Bayer M, Camps G, Biadala L, Buil S, Quelin X, Hermier JP. Thermal activation of non-radiative Auger recombination in charged colloidal nanocrystals. Nat Nanotechnol 2013; 8:206-12. [PMID: 23396313 DOI: 10.1038/nnano.2012.260] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 12/17/2012] [Indexed: 05/19/2023]
Abstract
Applications of semiconductor nanocrystals such as biomarkers and light-emitting optoelectronic devices require that their fluorescence quantum yield be close to 100%. However, such quantum yields have not been obtained yet, in part, because non-radiative Auger recombination in charged nanocrystals could not be suppressed completely. Here, we synthesize colloidal core/thick-shell CdSe/CdS nanocrystals with 100% quantum yield and completely quenched Auger processes at low temperatures, although the nanocrystals are negatively photocharged. Single particle and ensemble spectroscopy in the temperature range 30-300 K shows that the non-radiative Auger recombination is thermally activated around 200 K. Experimental results are well described by a model suggesting a temperature-dependent delocalization of one of the trion electrons from the CdSe core and enhanced Auger recombination at the abrupt CdS outer surface. These results point to a route for the design of core/shell structures with 100% quantum yield at room temperature.
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Affiliation(s)
- C Javaux
- Laboratoire de Physique et d'Etude des Matériaux, CNRS, ESPCI, 10 rue Vauquelin 75231 Paris, France
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Teperino R, Amann S, Bayer M, McGee SL, Loipetzberger A, Connor T, Jaeger C, Kammerer B, Winter L, Wiche G, Dalgaard K, Selvaraj M, Gaster M, Lee-Young RS, Febbraio MA, Knauf C, Cani PD, Aberger F, Penninger JM, Pospisilik JA, Esterbauer H. Hedgehog partial agonism drives Warburg-like metabolism in muscle and brown fat. Cell 2012; 151:414-26. [PMID: 23063129 DOI: 10.1016/j.cell.2012.09.021] [Citation(s) in RCA: 209] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 06/18/2012] [Accepted: 09/17/2012] [Indexed: 02/04/2023]
Abstract
Diabetes, obesity, and cancer affect upward of 15% of the world's population. Interestingly, all three diseases juxtapose dysregulated intracellular signaling with altered metabolic state. Exactly which genetic factors define stable metabolic set points in vivo remains poorly understood. Here, we show that hedgehog signaling rewires cellular metabolism. We identify a cilium-dependent Smo-Ca(2+)-Ampk axis that triggers rapid Warburg-like metabolic reprogramming within minutes of activation and is required for proper metabolic selectivity and flexibility. We show that Smo modulators can uncouple the Smo-Ampk axis from canonical signaling and identify cyclopamine as one of a new class of "selective partial agonists," capable of concomitant inhibition of canonical and activation of noncanonical hedgehog signaling. Intriguingly, activation of the Smo-Ampk axis in vivo drives robust insulin-independent glucose uptake in muscle and brown adipose tissue. These data identify multiple noncanonical endpoints that are pivotal for rational design of hedgehog modulators and provide a new therapeutic avenue for obesity and diabetes.
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Affiliation(s)
- Raffaele Teperino
- Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, D-79108 Freiburg, Germany
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Langer L, Poltavtsev SV, Yugova IA, Yakovlev DR, Karczewski G, Wojtowicz T, Kossut J, Akimov IA, Bayer M. Magnetic-field control of photon echo from the electron-trion system in a CdTe quantum well: shuffling coherence between optically accessible and inaccessible states. Phys Rev Lett 2012; 109:157403. [PMID: 23102368 DOI: 10.1103/physrevlett.109.157403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Indexed: 06/01/2023]
Abstract
We report on magnetic field-induced oscillations of the photon echo signal from negatively charged excitons in a CdTe/(Cd,Mg)Te semiconductor quantum well. The oscillatory signal is due to Larmor precession of the electron spin about a transverse magnetic field and depends sensitively on the polarization configuration of the exciting and refocusing pulses. The echo amplitude can be fully tuned from the maximum down to zero depending on the time delay between the two pulses and the magnetic-field strength. The results are explained in terms of the optical Bloch equations accounting for the spin level structure of electrons and trions.
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Affiliation(s)
- L Langer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
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Li Y, Sinitsyn N, Smith DL, Reuter D, Wieck AD, Yakovlev DR, Bayer M, Crooker SA. Intrinsic spin fluctuations reveal the dynamical response function of holes coupled to nuclear spin baths in (In,Ga)As quantum dots. Phys Rev Lett 2012; 108:186603. [PMID: 22681099 DOI: 10.1103/physrevlett.108.186603] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Indexed: 06/01/2023]
Abstract
The problem of how single central spins interact with a nuclear spin bath is essential for understanding decoherence and relaxation in many quantum systems, yet is highly nontrivial owing to the many-body couplings involved. Different models yield widely varying time scales and dynamical responses (exponential, power-law, gaussian, etc.). Here we detect the small random fluctuations of central spins in thermal equilibrium [holes in singly charged (In,Ga)As quantum dots] to reveal the time scales and functional form of bath-induced spin relaxation. This spin noise indicates long (400 ns) spin correlation times at a zero magnetic field that increase to ∼5 μs as dominant hole-nuclear relaxation channels are suppressed with small (100 G) applied fields. Concomitantly, the noise line shape evolves from Lorentzian to power law, indicating a crossover from exponential to slow [∼1/log(t)] dynamics.
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Affiliation(s)
- Yan Li
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Spatzek S, Greilich A, Economou SE, Varwig S, Schwan A, Yakovlev DR, Reuter D, Wieck AD, Reinecke TL, Bayer M. Optical control of coherent interactions between electron spins in InGaAs quantum dots. Phys Rev Lett 2011; 107:137402. [PMID: 22026903 DOI: 10.1103/physrevlett.107.137402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Indexed: 05/31/2023]
Abstract
Coherent interactions between spins in quantum dots are a key requirement for quantum gates. We have performed pump-probe experiments in which pulsed lasers emitting at different photon energies manipulate two distinct subsets of electron spins within an inhomogeneous InGaAs quantum dot ensemble. The spin dynamics are monitored through their precession about an external magnetic field. These measurements demonstrate spin precession phase shifts and modulations of the magnitude of one subset of oriented spins after optical orientation of the second subset. The observations are consistent with results from a model using a Heisenberg-like interaction with μeV strength.
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Affiliation(s)
- S Spatzek
- Experimentelle Physik, Technische Universität Dortmund, Germany
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Graham J, Hackett CA, Smith K, Woodhead M, MacKenzie K, Tierney I, Cooke D, Bayer M, Jennings N. Towards an understanding of the nature of resistance to Phytophthora root rot in red raspberry. Theor Appl Genet 2011; 123:585-601. [PMID: 21573956 DOI: 10.1007/s00122-011-1609-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 04/26/2011] [Indexed: 05/20/2023]
Abstract
A mapping population segregating for root rot resistance was screened under both field and glasshouse conditions over a number of seasons. Few correlations between field and glasshouse scores were significant. Final root rot scores were significantly negatively correlated with measures of root vigour. Two QTL associated with resistance were identified as were overlapping QTL for root vigour assessments. Markers significantly associated with the traits were used to identify BAC clones, which were subsequently sequenced to examine gene content. A number of genes were identified including those associated with stem cell identity, cell proliferation and elongation in the root zone, control of meristematic activity and organisation, cell signalling, stress response, sugar sensing and control of gene expression as well as a range of transcription factors including those known to be associated with defence. For marker-assisted breeding, the SSR marker Rub118b 110 bp allele from Latham was found in resistant germplasm but was not found in any of the susceptible germplasm tested.
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Affiliation(s)
- J Graham
- Genetics Department, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK.
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Belotelov VI, Akimov IA, Pohl M, Kalish AN, Kasture S, Vengurlekar AS, Gopal AV, Kotov VA, Yakovlev D, Zvezdin AK, Bayer M. Intensity magnetooptical effect in magnetoplasmonic crystals. ACTA ACUST UNITED AC 2011. [DOI: 10.1088/1742-6596/303/1/012038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Christen S, Holdener M, Beerli C, Thoma G, Bayer M, Pfeilschifter JM, Hintermann E, Zerwes HG, Christen U. Small molecule CXCR3 antagonist NIBR2130 has only a limited impact on type 1 diabetes in a virus-induced mouse model. Clin Exp Immunol 2011; 165:318-28. [PMID: 21649647 DOI: 10.1111/j.1365-2249.2011.04426.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
CXCL10 is one of the key chemokines involved in trafficking of autoaggressive T cells to the islets of Langerhans during the autoimmune destruction of beta cells in type 1 diabetes (T1D). Blockade of CXCL10 or genetic deletion of its receptor CXCR3 results in a reduction of T1D in animal models. As an alternative to the use of neutralizing monoclonal antibodies to CXCL10 or CXCR3 we evaluated the small molecule CXCR3 antagonist NIBR2130 in a virus-induced mouse model for T1D. We found that the overall frequency of T1D was not reduced in mice administered with NIBR2130. An initial slight delay of diabetes onset was not stable over time, because the mice turned diabetic upon removal of the antagonist. Accordingly, no significant differences were found in the islet infiltration rate and the frequency and activity of islet antigen-specific T cells between protected mice administered with NIBR2130 and control mice. Our data indicate that in contrast to direct inhibition of CXCL10, blockade of CXCR3 with the small molecule antagonist NIBR2130 has no impact on trafficking and/or activation of autoaggressive T cells and is not sufficient to prevent T1D.
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Affiliation(s)
- S Christen
- Pharmazentrum Frankfurt/ZAFES, Klinikum der Goethe Universität, Frankfurt am Main, Germany.
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