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Shrestha S, Li X, Tsai H, Hou CH, Huang HH, Ghosh D, Shyue JJ, Wang L, Tretiak S, Ma X, Nie W. Long carrier diffusion length in two-dimensional lead halide perovskite single crystals. Chem 2022. [DOI: 10.1016/j.chempr.2022.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Jung J, Odobesko A, Boshuis R, Szczerbakow A, Story T, Bode M. Systematic Investigation of the Coupling between One-Dimensional Edge States of a Topological Crystalline Insulator. PHYSICAL REVIEW LETTERS 2021; 126:236402. [PMID: 34170152 DOI: 10.1103/physrevlett.126.236402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
The interaction of spin-polarized one-dimensional (1D) topological edge modes localized along single-atomic steps of the topological crystalline insulator Pb_{0.7}Sn_{0.3}Se(001) has been studied systematically by scanning tunneling spectroscopy. Our results reveal that the coupling of adjacent edge modes sets in at a step-to-step distance d_{ss}≤25 nm, resulting in a characteristic splitting of a single peak at the Dirac point in tunneling spectra. Whereas the energy splitting exponentially increases with decreasing d_{ss} for single-atomic steps running almost parallel, we find no splitting for single-atomic step edges under an angle of 90°. The results are discussed in terms of overlapping wave functions with p_{x}, p_{y} orbital character.
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Affiliation(s)
- Johannes Jung
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Artem Odobesko
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Robin Boshuis
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Andrzej Szczerbakow
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Tomasz Story
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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Tang KW, Li S, Weeden S, Song Z, McClintock L, Xiao R, Senger RT, Yu D. Transport Modeling of Locally Photogenerated Excitons in Halide Perovskites. J Phys Chem Lett 2021; 12:3951-3959. [PMID: 33872028 DOI: 10.1021/acs.jpclett.1c00507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Excitons have fundamental impacts on optoelectronic properties of semiconductors. Halide perovskites, with long carrier lifetimes and ionic crystal structures, may support highly mobile excitons because the dipolar nature of excitons suppresses phonon scattering. Inspired by recent experimental progress, we perform device modeling to rigorously analyze exciton formation and transport in methylammonium lead triiodide under local photoexcitation by using a finite element method. Mobile excitons, coexisting with free carriers, can dominate photocurrent generation at low temperatures. The simulation results are in excellent agreement with the experimentally observed strong temperature and gate dependence of carrier diffusion. This work signifies that efficient exciton transport can substantially influence charge transport in the family of perovskite materials.
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Affiliation(s)
- Kuen Wai Tang
- Department of Physics and Astronomy, University of California-Davis, One Shields Avenue, Davis, California 95616, United States
| | - Senlei Li
- Department of Physics and Astronomy, University of California-Davis, One Shields Avenue, Davis, California 95616, United States
| | - Spencer Weeden
- Department of Physics, Carleton College, Sayles Hill Campus Center, North College Street, Northfield, Minnesota 55057, United States
| | - Ziyi Song
- Department of Physics and Astronomy, University of California-Davis, One Shields Avenue, Davis, California 95616, United States
| | - Luke McClintock
- Department of Physics and Astronomy, University of California-Davis, One Shields Avenue, Davis, California 95616, United States
| | - Rui Xiao
- Department of Physics and Astronomy, University of California-Davis, One Shields Avenue, Davis, California 95616, United States
| | - R Tugrul Senger
- Department of Physics, Izmir Institute of Technology, 35430 Izmir, Turkey
| | - Dong Yu
- Department of Physics and Astronomy, University of California-Davis, One Shields Avenue, Davis, California 95616, United States
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Sun Z, Millis AJ. Topological Charge Pumping in Excitonic Insulators. PHYSICAL REVIEW LETTERS 2021; 126:027601. [PMID: 33512198 DOI: 10.1103/physrevlett.126.027601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
We show that in excitonic insulators with s-wave electron-hole pairing, an applied electric field (either pulsed or static) can induce a p-wave component to the order parameter, and further drive it to rotate in the s+ip plane, realizing a Thouless charge pump. In one dimension, each cycle of rotation pumps exactly two electrons across the sample. Higher dimensional systems can be viewed as a stack of one-dimensional chains in momentum space in which each chain crossing the Fermi surface contributes a channel of charge pumping. Physics beyond the adiabatic limit, including in particular dissipative effects is discussed.
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Affiliation(s)
- Zhiyuan Sun
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, USA
| | - Andrew J Millis
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, USA
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
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Kim HS, Hwang TH, Kim NH, Hou Y, Yu D, Sim HS, Doh YJ. Adjustable Quantum Interference Oscillations in Sb-Doped Bi 2Se 3 Topological Insulator Nanoribbons. ACS NANO 2020; 14:14118-14125. [PMID: 33030335 DOI: 10.1021/acsnano.0c06892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Topological insulator (TI) nanoribbons (NRs) provide a platform for investigating quantum interference oscillations combined with topological surface states. One-dimensional subbands formed along the perimeter of a TI NR can be modulated by an axial magnetic field, exhibiting Aharonov-Bohm (AB) and Altshuler-Aronov-Spivak (AAS) oscillations of magnetoconductance (MC). Using Sb-doped Bi2Se3 TI NRs, we found that the relative amplitudes of the two quantum oscillations can be tuned by varying the channel length, exhibiting crossover from quasi-ballistic to diffusive transport regimes. The AB and AAS oscillations were discernible even for a 70 μm long channel, while only the AB oscillations were observed for a short channel. Analyses based on ensemble-averaged fast Fourier transform of MC curves revealed exponential temperature dependences of the AB and AAS oscillations, from which the circumferential phase-coherence length and thermal length were obtained. Our observations indicate that the channel length in a TI NR can be a useful control knob for tailored quantum interference oscillations, especially for developing topological hybrid quantum devices.
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Affiliation(s)
- Hong-Seok Kim
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Tae-Ha Hwang
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Nam-Hee Kim
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Yasen Hou
- Department of Physics, University of California, Davis, California 95616, United States
| | - Dong Yu
- Department of Physics, University of California, Davis, California 95616, United States
| | - H-S Sim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Yong-Joo Doh
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
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McClintock L, Xiao R, Hou Y, Gibson C, Travaglini HC, Abramovitch D, Tan LZ, Senger RT, Fu Y, Jin S, Yu D. Temperature and Gate Dependence of Carrier Diffusion in Single Crystal Methylammonium Lead Iodide Perovskite Microstructures. J Phys Chem Lett 2020; 11:1000-1006. [PMID: 31958953 DOI: 10.1021/acs.jpclett.9b03643] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We investigate temperature-dependent photogenerated carrier diffusion in single-crystal methylammonium lead iodide microstuctures via scanning photocurrent microscopy. Carrier diffusion lengths increased abruptly across the tetragonal to orthorhombic phase transition and reached 200 ± 50 μm at 80 K. In combination with the microsecond carrier lifetime measured by a transient photocurrent method, an enormous carrier mobility value of 3 × 104 cm2/V s was extracted at 80 K. The observed highly nonlocal photocurrent and the rapid increase of the carrier diffusion length at low temperatures can be understood by the formation and efficient transport of free excitons in the orthorhombic phase as a result of reduced optical phonon scattering due to the dipolar nature of the excitons. Carrier diffusion lengths were tuned by a factor of 8 by gate voltage and increased with increasing majority carrier (electron) concentration, consistent with the exciton model.
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Affiliation(s)
- Luke McClintock
- Department of Physics , University of California-Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Rui Xiao
- Department of Physics , University of California-Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Yasen Hou
- Department of Physics , University of California-Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Clinton Gibson
- Department of Physics , University of California-Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Henry Clark Travaglini
- Department of Physics , University of California-Davis , One Shields Avenue , Davis , California 95616 , United States
| | - David Abramovitch
- Department of Physics , University of California-Berkeley , 366 LeConte Hall , Berkeley , California 94720 , United States
- Molecular Foundry , Lawrence Berkeley Laboratory , 67 Cyclotron Road , Berkeley , California 94720 , United States
| | - Liang Z Tan
- Molecular Foundry , Lawrence Berkeley Laboratory , 67 Cyclotron Road , Berkeley , California 94720 , United States
| | | | - Yongping Fu
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States
| | - Song Jin
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States
| | - Dong Yu
- Department of Physics , University of California-Davis , One Shields Avenue , Davis , California 95616 , United States
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