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Ksenzov D, Maznev AA, Unikandanunni V, Bencivenga F, Capotondi F, Caretta A, Foglia L, Malvestuto M, Masciovecchio C, Mincigrucci R, Nelson KA, Pancaldi M, Pedersoli E, Randolph L, Rahmann H, Urazhdin S, Bonetti S, Gutt C. Nanoscale Transient Magnetization Gratings Created and Probed by Femtosecond Extreme Ultraviolet Pulses. NANO LETTERS 2021; 21:2905-2911. [PMID: 33724854 DOI: 10.1021/acs.nanolett.0c05083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We utilize coherent femtosecond extreme ultraviolet (EUV) pulses from a free electron laser (FEL) to generate transient periodic magnetization patterns with periods as short as 44 nm. Combining spatially periodic excitation with resonant probing at the M-edge of cobalt allows us to create and probe transient gratings of electronic and magnetic excitations in a CoGd alloy. In a demagnetized sample, we observe an electronic excitation with a rise time close to the FEL pulse duration and ∼0.5 ps decay time indicative of electron-phonon relaxation. When the sample is magnetized to saturation in an external field, we observe a magnetization grating, which appears on a subpicosecond time scale as the sample is demagnetized at the maxima of the EUV intensity and then decays on the time scale of tens of picoseconds via thermal diffusion. The described approach opens multiple avenues for studying dynamics of ultrafast magnetic phenomena on nanometer length scales.
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Affiliation(s)
- Dmitriy Ksenzov
- Department Physik, Universität Siegen, Walter-Flex-Strasse 3, 57072, Siegen, Germany
| | - Alexei A Maznev
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | | | - Filippo Bencivenga
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Flavio Capotondi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Antonio Caretta
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Laura Foglia
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Marco Malvestuto
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Claudio Masciovecchio
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Riccardo Mincigrucci
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Keith A Nelson
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Matteo Pancaldi
- Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
| | - Emanuele Pedersoli
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza, Italy
| | - Lisa Randolph
- Department Physik, Universität Siegen, Walter-Flex-Strasse 3, 57072, Siegen, Germany
| | - Hendrik Rahmann
- Department Physik, Universität Siegen, Walter-Flex-Strasse 3, 57072, Siegen, Germany
| | - Sergei Urazhdin
- Department of Physics, Emory University, Atlanta, Georgia 30322, United States
| | - Stefano Bonetti
- Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
- Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, 30172 Venice, Italy
| | - Christian Gutt
- Department Physik, Universität Siegen, Walter-Flex-Strasse 3, 57072, Siegen, Germany
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Bencivenga F, Mincigrucci R, Capotondi F, Foglia L, Naumenko D, Maznev AA, Pedersoli E, Simoncig A, Caporaletti F, Chiloyan V, Cucini R, Dallari F, Duncan RA, Frazer TD, Gaio G, Gessini A, Giannessi L, Huberman S, Kapteyn H, Knobloch J, Kurdi G, Mahne N, Manfredda M, Martinelli A, Murnane M, Principi E, Raimondi L, Spampinati S, Spezzani C, Trovò M, Zangrando M, Chen G, Monaco G, Nelson KA, Masciovecchio C. Nanoscale transient gratings excited and probed by extreme ultraviolet femtosecond pulses. SCIENCE ADVANCES 2019; 5:eaaw5805. [PMID: 31360768 PMCID: PMC6660206 DOI: 10.1126/sciadv.aaw5805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/20/2019] [Indexed: 05/27/2023]
Abstract
Advances in developing ultrafast coherent sources operating at extreme ultraviolet (EUV) and x-ray wavelengths allow the extension of nonlinear optical techniques to shorter wavelengths. Here, we describe EUV transient grating spectroscopy, in which two crossed femtosecond EUV pulses produce spatially periodic nanoscale excitations in the sample and their dynamics is probed via diffraction of a third time-delayed EUV pulse. The use of radiation with wavelengths down to 13.3 nm allowed us to produce transient gratings with periods as short as 28 nm and observe thermal and coherent phonon dynamics in crystalline silicon and amorphous silicon nitride. This approach allows measurements of thermal transport on the ~10-nm scale, where the two samples show different heat transport regimes, and can be applied to study other phenomena showing nontrivial behaviors at the nanoscale, such as structural relaxations in complex liquids and ultrafast magnetic dynamics.
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Affiliation(s)
- F. Bencivenga
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - R. Mincigrucci
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - F. Capotondi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - L. Foglia
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - D. Naumenko
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - A. A. Maznev
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - E. Pedersoli
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - A. Simoncig
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - F. Caporaletti
- Department of Physics, University of Trento, Via Sommarive 14, Povo (TN), Italy
| | - V. Chiloyan
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - R. Cucini
- IOM-CNR, Strada Statale 14, km 163.5, in Area Science Park, I-34012 Basovizza (TS), Italy
| | - F. Dallari
- Department of Physics, University of Trento, Via Sommarive 14, Povo (TN), Italy
| | - R. A. Duncan
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - T. D. Frazer
- JILA and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - G. Gaio
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - A. Gessini
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - L. Giannessi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - S. Huberman
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - H. Kapteyn
- JILA and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - J. Knobloch
- JILA and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - G. Kurdi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - N. Mahne
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
- IOM-CNR, Strada Statale 14, km 163.5, in Area Science Park, I-34012 Basovizza (TS), Italy
| | - M. Manfredda
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - A. Martinelli
- Department of Physics, University of Trento, Via Sommarive 14, Povo (TN), Italy
| | - M. Murnane
- JILA and Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - E. Principi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - L. Raimondi
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - S. Spampinati
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - C. Spezzani
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - M. Trovò
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
| | - M. Zangrando
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
- IOM-CNR, Strada Statale 14, km 163.5, in Area Science Park, I-34012 Basovizza (TS), Italy
| | - G. Chen
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - G. Monaco
- Department of Physics, University of Trento, Via Sommarive 14, Povo (TN), Italy
| | - K. A. Nelson
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - C. Masciovecchio
- Elettra Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, 34149 Basovizza (TS), Italy
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Fu J, Penteado PH, Hachiya MO, Loss D, Egues JC. Persistent Skyrmion Lattice of Noninteracting Electrons with Spin-Orbit Coupling. PHYSICAL REVIEW LETTERS 2016; 117:226401. [PMID: 27925749 DOI: 10.1103/physrevlett.117.226401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Indexed: 06/06/2023]
Abstract
A persistent spin helix (PSH) is a robust helical spin-density pattern arising in disordered 2D electron gases with Rashba α and Dresselhaus β spin-orbit (SO) tuned couplings, i.e., α=±β. Here, we investigate the emergence of a persistent Skyrmion lattice (PSL) resulting from the coherent superposition of PSHs along orthogonal directions-crossed PSHs-in wells with two occupied subbands ν=1, 2. For realistic GaAs wells, we show that the Rashba α_{ν} and Dresselhaus β_{ν} couplings can be simultaneously tuned to equal strengths but opposite signs, e.g., α_{1}=β_{1} and α_{2}=-β_{2}. In this regime, and away from band anticrossings, our noninteracting electron gas sustains a topologically nontrivial Skyrmion-lattice spin-density excitation, which inherits the robustness against spin-independent disorder and interactions from its underlying crossed PSHs. We find that the spin relaxation rate due to the interband SO coupling is comparable to that of the cubic Dresselhaus term as a mechanism of the PSL decay. Near anticrossings, the interband-induced spin mixing leads to unusual spin textures along the energy contours beyond those of the Rahsba-Dresselhaus bands. Our PSL opens up the unique possibility of observing topological phenomena, e.g., topological and Skyrmion Hall effects, in ordinary GaAs wells with noninteracting electrons.
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Affiliation(s)
- Jiyong Fu
- Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, São Paulo, Brazil
| | - Poliana H Penteado
- Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, São Paulo, Brazil
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Marco O Hachiya
- Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, São Paulo, Brazil
| | - Daniel Loss
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - J Carlos Egues
- Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, São Paulo, Brazil
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Altmann P, Hernandez FGG, Ferreira GJ, Kohda M, Reichl C, Wegscheider W, Salis G. Current-Controlled Spin Precession of Quasistationary Electrons in a Cubic Spin-Orbit Field. PHYSICAL REVIEW LETTERS 2016; 116:196802. [PMID: 27232032 DOI: 10.1103/physrevlett.116.196802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Indexed: 06/05/2023]
Abstract
Space- and time-resolved measurements of spin drift and diffusion are performed on a GaAs-hosted two-dimensional electron gas. For spins where forward drift is compensated by backward diffusion, we find a precession frequency in the absence of an external magnetic field. The frequency depends linearly on the drift velocity and is explained by the cubic Dresselhaus spin-orbit interaction, for which drift leads to a spin precession angle twice that of spins that diffuse the same distance.
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Affiliation(s)
- P Altmann
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - F G G Hernandez
- Instituto de Fisica, Universidade de São Paulo, São Paulo 05508-090, São Paulo, Brazil
| | - G J Ferreira
- Instituto de Fisica, Universidade Federal de Uberlândia, Uberlândia 38400-902, Minas Gerais, Brazil
| | - M Kohda
- Department of Materials Science, Tohoku University, 6-6-02 Aramaki-Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - C Reichl
- Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - W Wegscheider
- Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - G Salis
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
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5
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Kunihashi Y, Sanada H, Gotoh H, Onomitsu K, Kohda M, Nitta J, Sogawa T. Drift transport of helical spin coherence with tailored spin-orbit interactions. Nat Commun 2016; 7:10722. [PMID: 26952129 PMCID: PMC4786748 DOI: 10.1038/ncomms10722] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 01/14/2016] [Indexed: 11/10/2022] Open
Abstract
Most future information processing techniques using electron spins in non-magnetic semiconductors will require both the manipulation and transfer of spins without their coherence being lost. The spin–orbit effective magnetic field induced by drifting electrons enables us to rotate the electron spins in the absence of an external magnetic field. However, the fluctuations in the effective magnetic field originating from the random scattering of electrons also cause undesirable spin decoherence, which limits the length scale of the spin transport. Here we demonstrate the drift transport of electron spins adjusted to a robust spin structure, namely a persistent spin helix. We find that the persistent spin helix enhances the spatial coherence of drifting spins, resulting in maximized spin decay length near the persistent spin helix condition. Within the enhanced distance of the spin transport, the transport path of electron spins can be modulated by employing time-varying in-plane voltages. Spin-orbit effects in non-magnetic semiconductors allow for the manipulation of electronic spins in the absence of an applied magnetic field. Here, the authors exploit a persistent spin helix state in single quantum wells to enhance the coherence length of electronic drift transport.
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Affiliation(s)
- Y Kunihashi
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - H Sanada
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - H Gotoh
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - K Onomitsu
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - M Kohda
- Department of Materials Science, Tohoku University, 6-6-02 Aramaki-Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - J Nitta
- Department of Materials Science, Tohoku University, 6-6-02 Aramaki-Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - T Sogawa
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
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Vega-Flick A, Eliason JK, Maznev AA, Khanolkar A, Abi Ghanem M, Boechler N, Alvarado-Gil JJ, Nelson KA. Laser-induced transient grating setup with continuously tunable period. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:123101. [PMID: 26724000 DOI: 10.1063/1.4936767] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present a modification of the laser-induced transient grating setup enabling continuous tuning of the transient grating period. The fine control of the period is accomplished by varying the angle of the diffraction grating used to split excitation and probe beams. The setup has been tested by measuring dispersion of bulk and surface acoustic waves in both transmission and reflection geometries. The presented modification is fully compatible with optical heterodyne detection and can be easily implemented in any transient grating setup.
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Affiliation(s)
- A Vega-Flick
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - J K Eliason
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A A Maznev
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Khanolkar
- Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - M Abi Ghanem
- Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - N Boechler
- Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - J J Alvarado-Gil
- Applied Physics Department, CINVESTAV-Unidad Mérida, Carretera Antigua a Progreso Km 6, Cordemex, Mérida, Yucatán 97310 Mexico
| | - K A Nelson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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