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Qian C, Villafañe V, Petrić MM, Soubelet P, Stier AV, Finley JJ. Coupling of MoS_{2} Excitons with Lattice Phonons and Cavity Vibrational Phonons in Hybrid Nanobeam Cavities. Phys Rev Lett 2023; 130:126901. [PMID: 37027879 DOI: 10.1103/physrevlett.130.126901] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 01/23/2023] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
We report resonant Raman spectroscopy of neutral excitons X^{0} and intravalley trions X^{-} in hBN-encapsulated MoS_{2} monolayer embedded in a nanobeam cavity. By temperature tuning the detuning between Raman modes of MoS_{2} lattice phonons and X^{0}/X^{-} emission peaks, we probe the mutual coupling of excitons, lattice phonons and cavity vibrational phonons. We observe an enhancement of X^{0}-induced Raman scattering and a suppression for X^{-}-induced, and explain our findings as arising from the tripartite exciton-phonon-phonon coupling. The cavity vibrational phonons provide intermediate replica states of X^{0} for resonance conditions in the scattering of lattice phonons, thus enhancing the Raman intensity. In contrast, the tripartite coupling involving X^{-} is found to be much weaker, an observation explained by the geometry-dependent polarity of the electron and hole deformation potentials. Our results indicate that phononic hybridization between lattice and nanomechanical modes plays a key role in the excitonic photophysics and light-matter interaction in 2D-material nanophotonic systems.
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Affiliation(s)
- Chenjiang Qian
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Viviana Villafañe
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Marko M Petrić
- Walter Schottky Institut and Department of Electrical and Computer Engineering, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Pedro Soubelet
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Andreas V Stier
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Jonathan J Finley
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
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2
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Ren L, Lombez L, Robert C, Beret D, Lagarde D, Urbaszek B, Renucci P, Taniguchi T, Watanabe K, Crooker SA, Marie X. Optical Detection of Long Electron Spin Transport Lengths in a Monolayer Semiconductor. Phys Rev Lett 2022; 129:027402. [PMID: 35867459 DOI: 10.1103/physrevlett.129.027402] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Using a spatially resolved optical pump-probe experiment, we measure the lateral transport of spin-valley polarized electrons over very long distances (tens of micrometers) in a single WSe_{2} monolayer. By locally pumping the Fermi sea of 2D electrons to a high degree of spin-valley polarization (up to 75%) using circularly polarized light, the lateral diffusion of the electron polarization can be mapped out via the photoluminescence induced by a spatially separated and linearly polarized probe laser. Up to 25% spin-valley polarization is observed at pump-probe separations up to 20 μm. Characteristic spin-valley diffusion lengths of 18±3 μm are revealed at low temperatures. The dependence on temperature, pump helicity, pump intensity, and electron density highlight the key roles played by spin relaxation time and pumping efficiency on polarized electron transport in monolayer semiconductors possessing spin-valley locking.
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Affiliation(s)
- L Ren
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - L Lombez
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - C Robert
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - D Beret
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - D Lagarde
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - B Urbaszek
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - P Renucci
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-00044, Japan
| | - S A Crooker
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - X Marie
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
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3
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Abstract
Colloidal semiconductor nanoplatelets (NPLs) are a scalable materials platform for optoelectronic applications requiring fast and narrow emission, including spin-to-photon transduction within quantum information networks. In particular, three-particle negative trions of NPLs are appealing emitters since, unlike excitons, they do not have an optically "dark" sublevel. In CdSe NPLs, trion emission dominates the photoluminescence (PL) spectrum at low temperature but using them as single photon-emitting states requires more knowledge about their preparation, since trions in these materials are not directly optically accessible from the ground state. This work demonstrates, using power-dependent time-resolved transient absorptions (TA) of CdSe NPLs, that trions form via biexciton decay in 1.6 ps. The scaling of the trion population and formation lifetime with excitation power indicates that they do not form through collisional mechanisms typical for 2D materials, but rather by a unimolecular hole transfer. This work is a step toward deterministic single photon emission from trions.
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Affiliation(s)
- Albert F Vong
- Department of Materials Science and Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Shawn Irgen-Gioro
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Yue Wu
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Emily A Weiss
- Department of Materials Science and Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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4
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Robert C, Park S, Cadiz F, Lombez L, Ren L, Tornatzky H, Rowe A, Paget D, Sirotti F, Yang M, Van Tuan D, Taniguchi T, Urbaszek B, Watanabe K, Amand T, Dery H, Marie X. Spin/valley pumping of resident electrons in WSe 2 and WS 2 monolayers. Nat Commun 2021; 12:5455. [PMID: 34526493 PMCID: PMC8443707 DOI: 10.1038/s41467-021-25747-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 05/04/2021] [Accepted: 08/31/2021] [Indexed: 11/09/2022] Open
Abstract
Monolayers of transition metal dichalcogenides are ideal materials to control both spin and valley degrees of freedom either electrically or optically. Nevertheless, optical excitation mostly generates excitons species with inherently short lifetime and spin/valley relaxation time. Here we demonstrate a very efficient spin/valley optical pumping of resident electrons in n-doped WSe2 and WS2 monolayers. We observe that, using a continuous wave laser and appropriate doping and excitation densities, negative trion doublet lines exhibit circular polarization of opposite sign and the photoluminescence intensity of the triplet trion is more than four times larger with circular excitation than with linear excitation. We interpret our results as a consequence of a large dynamic polarization of resident electrons using circular light.
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Affiliation(s)
- Cedric Robert
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France.
| | - Sangjun Park
- Physique de la matière condensée, Ecole Polytechnique, CNRS, IP Paris, 91128, Paris, Palaiseau, France
| | - Fabian Cadiz
- Physique de la matière condensée, Ecole Polytechnique, CNRS, IP Paris, 91128, Paris, Palaiseau, France.
| | - Laurent Lombez
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France
| | - Lei Ren
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France
| | - Hans Tornatzky
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France
| | - Alistair Rowe
- Physique de la matière condensée, Ecole Polytechnique, CNRS, IP Paris, 91128, Paris, Palaiseau, France
| | - Daniel Paget
- Physique de la matière condensée, Ecole Polytechnique, CNRS, IP Paris, 91128, Paris, Palaiseau, France
| | - Fausto Sirotti
- Physique de la matière condensée, Ecole Polytechnique, CNRS, IP Paris, 91128, Paris, Palaiseau, France
| | - Min Yang
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, 14627, USA
| | - Dinh Van Tuan
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, 14627, USA
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-00044, Japan
| | - Bernhard Urbaszek
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-00044, Japan
| | - Thierry Amand
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France
| | - Hanan Dery
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, 14627, USA
- Department of Physics, University of Rochester, Rochester, NY, 14627, USA
| | - Xavier Marie
- Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France.
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5
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Riche F, Bragança H, Qu F, Lopez-Richard V, Xie SJ, Dias AC, Marques GE. Robust room temperature emissions of trion in darkish WSe 2monolayers: effects of dark neutral and charged excitonic states. J Phys Condens Matter 2020; 32:365702. [PMID: 32365339 DOI: 10.1088/1361-648x/ab8fd4] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Owing to nonzero charge and spin degrees of freedom, trions offer unprecedented tunability and open new paths for applications in devices based on 2D semiconductors. However, in monolayer WSe2, the trion photoluminescence is commonly detected only at low temperatures and vanishes at room temperature, which undermines practical applications. To unveil how to overcome this obstacle, we have developed a comprehensive theory to probe the impact of different excitonic channels on the trion emission in WSe2monolayers, which combinesab initiotight-binding formalism, Bethe-Salpeter equation and a set of coupled rate equations to describe valley dynamics of excitonic particles. Through a systematic study in which new scattering channels are progressively included, we found that, besides the low electron density, strong many-body correlations between bright and dark excitonic states quenches the trion emission in WSe2. Therefore, the reduction of scatterings from bright to dark states is required to achieve trion emission at room temperature for experimentally accessible carrier concentrations.
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Affiliation(s)
- Flavio Riche
- Instituto de Física, Universidade de Brasília, Brasília-DF, Brazil
| | - Helena Bragança
- Departamento de Física, Universidade Federal de Ouro Preto, Ouro Preto-MG, Brazil
- Departamento de Física, Universidade Federal de São Carlos, São Carlos-SP, Brazil
| | - Fanyao Qu
- Instituto de Física, Universidade de Brasília, Brasília-DF, Brazil
| | - Victor Lopez-Richard
- Departamento de Física, Universidade Federal de São Carlos, São Carlos-SP, Brazil
| | - S J Xie
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, People's Republic of China
| | - A C Dias
- Instituto de Física, Universidade de Brasília, Brasília-DF, Brazil
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6
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Liu B, Zhao W, Ding Z, Verzhbitskiy I, Li L, Lu J, Chen J, Eda G, Loh KP. Engineering Bandgaps of Monolayer MoS2 and WS2 on Fluoropolymer Substrates by Electrostatically Tuned Many-Body Effects. Adv Mater 2016; 28:6457-6464. [PMID: 27184600 DOI: 10.1002/adma.201504876] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 04/11/2016] [Indexed: 06/05/2023]
Abstract
Intrinsic electrical and excitonic properties of monolayer transition-metal dichalcogenides can be revealed on CYTOP fluoropolymer substrates with greatly suppressed unintentional doping and dielectric screening. Ambipolar transport behavior is observed in monolayer WS2 by applying solid-state back gates. The excitonic properties of monolayer MoS2 and WS2 are determined by intricate interplays between the bandgap renormalization, Pauli blocking, and carrier screening against carrier doping.
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Affiliation(s)
- Bo Liu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| | - Weijie Zhao
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Zijing Ding
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Ivan Verzhbitskiy
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Linjun Li
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| | - Junpeng Lu
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Jianyi Chen
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Goki Eda
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
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7
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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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