1
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Yu Q, Feng S, Yu J, Cheng S, Lai Y, Chen Y, He K. Manipulation of Helicity-Dependent Photocurrent and Stokes Parameter Detection in Topological Insulator Bi 2Te 3 Nanowires. ACS APPLIED MATERIALS & INTERFACES 2024; 16:40297-40308. [PMID: 39016434 DOI: 10.1021/acsami.4c11221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Helicity-dependent photocurrent (HDPC) and its modulation in topological insulator Bi2Te3 nanowires have been investigated. It is revealed that when the incident plane of a laser is perpendicular to the nanowire, the HDPC is an odd function of the incident angle, which is mainly contributed by the circular photogalvanic effect originating from the surface states of Bi2Te3 nanowire. When the incident plane of a laser is parallel to the nanowire, the HDPC is approximately an even function of the incident angle, which is due to the circular photon drag effect coming from the surface states. It is found that the HDPC can be effectively tuned by the back gate and the ionic liquid top gate. By analyzing the substrate dependence of the HDPC, we find that the HDPC of the Bi2Te3 nanowire on the Si substrate is an order of magnitude larger than that on SiO2, which may be due to the spin injection from the Si substrate to the Bi2Te3 nanowire. In addition, by applying different biases, the Stokes parameters of a polarized light can be extracted by arithmetic operation of the photocurrents measured in the Bi2Te3 nanowire. This work suggests that topological insulator Bi2Te3 nanowires may provide a good platform for opto-spintronic devices, especially in chirality and polarimtry detection.
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Affiliation(s)
- Qin Yu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Shizun Feng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Jinling Yu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
- Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Shuying Cheng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Yunfeng Lai
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, Fujian, China
| | - Yonghai Chen
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ke He
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
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2
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Connelly BC, Taylor PJ, de Coster GJ. Emergence of threefold symmetric helical photocurrents in epitaxial low twinned Bi 2Se 3. Proc Natl Acad Sci U S A 2024; 121:e2307425121. [PMID: 38271339 PMCID: PMC10835140 DOI: 10.1073/pnas.2307425121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/29/2023] [Indexed: 01/27/2024] Open
Abstract
We present evidence of a strong circular photon drag effect (PDE) in topological insulators (TIs) through the observation of helicity-dependent topological photocurrents with threefold rotational symmetry using THz spectroscopy in epitaxially-grown Bi2Se3 with reduced crystallographic twinning. We establish how twinned domains introduce competing nonlinear optical (NLO) responses inherent to the crystal structure that obscure geometry-sensitive optical processes through the introduction of a spurious mirror symmetry. Minimizing the twinning defect reveals strong NLO response currents whose magnitude and direction depend on the alignment of the excitation to the crystal axes and follow the threefold rotational symmetry of the crystal. Notably, photocurrents arising from helical light reverse direction for left/right circular polarizations and maintain a strong azimuthal dependence-a result uniquely attributable to the circular PDE, where the photon momentum acts as an applied in-plane field stationary in the laboratory frame. Our results demonstrate new levels of control over the magnitude and direction of photocurrents in TIs and that the study of single-domain films is crucial to reveal hidden phenomena that couple topological order and crystal symmetries.
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Affiliation(s)
- Blair C. Connelly
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
| | - Patrick J. Taylor
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
| | - George J. de Coster
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
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3
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Wu W, Yu J, Chen YH, Liu Y, Cheng S, Lai Y, Sun J, Zhou H, He K. Electric Control of Helicity-Dependent Photocurrent and Surface Polarity Detection on Two-Dimensional Bi 2O 2Se Nanosheets. ACS NANO 2023; 17:16633-16643. [PMID: 37458508 DOI: 10.1021/acsnano.3c02812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Bismuth oxyselenide (Bi2O2Se) is a two-dimensional (2D) layered semiconductor material with high electron Hall mobility and excellent environmental stability as well as strong spin-orbit interaction (SOI), which has attracted intense attention for application in spintronic and spin optoelectronic devices. However, a comprehensive study of spin photocurrent and its microscopic origin in Bi2O2Se is still missing. Here, the helicity-dependent photocurrent (HDPC) was investigated in Bi2O2Se nanosheets. By analyzing the dependence of HDPC on the angle of incidence, we find that the HDPC originates from surface states with Cs symmetry in Bi2O2Se, which can be attributed to the circular photogalvanic effect (CPGE) and circular photon drag effect (CPDE). It is revealed that the HDPC current almost changes linearly with the source-drain voltage. Furthermore, we demonstrate effective tuning of HDPC in Bi2O2Se by ionic liquid gating, indicating that the spin splitting of the surface electronic structure is effectively tuned. By analyzing the gate voltage dependence of HDPC, we can unambiguously identify the surface polarity and the surface electronic structure of Bi2O2Se. The large HDPC in Bi2O2Se nanosheets and its efficient electrical tuning demonstrate that 2D Bi2O2Se nanosheets may provide a good platform for opto-spintronics devices.
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Affiliation(s)
- Wenyi Wu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
- International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, Guangdong, P. R. China
| | - Jinling Yu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
| | - Yong-Hai Chen
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yu Liu
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shuying Cheng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
| | - Yunfeng Lai
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
| | - Jie Sun
- National and Local United Engineering Laboratory of Flat Panel Display Technology, College of Physics and Information Engineering, Fuzhou University, Fuzhou 350100, China
- Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350100, China
| | - Hai Zhou
- International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, Guangdong, P. R. China
| | - Ke He
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
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4
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Liang G, Zhai G, Ma J, Wang H, Zhao J, Wu X, Zhang X. Circular Photogalvanic Current in Ni-Doped Cd 3As 2 Films Epitaxied on GaAs(111)B Substrate. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1979. [PMID: 37446495 DOI: 10.3390/nano13131979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023]
Abstract
Magnetic element doped Cd3As2 Dirac semimetal has attracted great attention for revealing the novel quantum phenomena and infrared opto-electronic applications. In this work, the circular photogalvanic effect (CPGE) was investigated at various temperatures for the Ni-doped Cd3As2 films which were grown on GaAs(111)B substrate by molecular beam epitaxy. The CPGE current generation was found to originate from the structural symmetry breaking induced by the lattice strain and magnetic doping in the Ni-doped Cd3As2 films, similar to that in the undoped ones. However, the CPGE current generated in the Ni-doped Cd3As2 films was approximately two orders of magnitude smaller than that in the undoped one under the same experimental conditions and exhibited a complex temperature variation. While the CPGE current in the undoped film showed a general increase with rising temperature. The greatly reduced CPGE current generation efficiency and its complex variation with temperature in the Ni-doped Cd3As2 films was discussed to result from the efficient capture of photo-generated carriers by the deep-level magnetic impurity bands and enhanced momentum relaxation caused by additional strong impurity scattering when magnetic dopants were introduced.
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Affiliation(s)
- Gaoming Liang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guihao Zhai
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jialin Ma
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hailong Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoguang Wu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinhui Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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5
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Hou B, Wang D, Barker BA, Qiu DY. Exchange-Driven Intermixing of Bulk and Topological Surface States by Chiral Excitons in Bi_{2}Se_{3}. PHYSICAL REVIEW LETTERS 2023; 130:216402. [PMID: 37295093 DOI: 10.1103/physrevlett.130.216402] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 02/17/2023] [Accepted: 05/01/2023] [Indexed: 06/12/2023]
Abstract
Topological surface states (TSS) in the prototypical topological insulator (TI) Bi_{2}Se_{3} are frequently characterized using optical probes, but electron-hole interactions and their effect on surface localization and optical response of the TSS remain unexplored. Here, we use ab initio calculations to understand excitonic effects in the bulk and surface of Bi_{2}Se_{3}. We identify multiple series of chiral excitons that exhibit both bulk and TSS character, due to exchange-driven mixing. Our results address fundamental questions about the degree to which electron-hole interactions can relax the topological protection of surface states and dipole selection rules for circularly polarized light in TIs by elucidating the complex intermixture of bulk and surface states excited in optical measurements and their coupling to light.
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Affiliation(s)
- Bowen Hou
- Department of Mechanical Engineering and Material Sciences, Yale University, New Haven, Connecticut 06511, USA
| | - Dan Wang
- Department of Mechanical Engineering and Material Sciences, Yale University, New Haven, Connecticut 06511, USA
| | - Bradford A Barker
- Department of Physics, University of California, Merced, California 95343, USA
| | - Diana Y Qiu
- Department of Mechanical Engineering and Material Sciences, Yale University, New Haven, Connecticut 06511, USA
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6
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Krishnamoorthy HNS, Dubrovkin AM, Adamo G, Soci C. Topological Insulator Metamaterials. Chem Rev 2023; 123:4416-4442. [PMID: 36943013 DOI: 10.1021/acs.chemrev.2c00594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Confinement of electromagnetic fields at the subwavelength scale via metamaterial paradigms is an established method to engineer light-matter interaction in most common material systems, from insulators to semiconductors and from metals to superconductors. In recent years, this approach has been extended to the realm of topological materials, providing a new avenue to access nontrivial features of their electronic band structure. In this review, we survey various topological material classes from a photonics standpoint, including crystal growth and lithographic structuring methods. We discuss how exotic electronic features such as spin-selective Dirac plasmon polaritons in topological insulators or hyperbolic plasmon polaritons in Weyl semimetals may give rise to unconventional magneto-optic, nonlinear, and circular photogalvanic effects in metamaterials across the visible to infrared spectrum. Finally, we dwell on how these effects may be dynamically controlled by applying external perturbations in the form of electric and magnetic fields or ultrafast optical pulses. Through these examples and future perspectives, we argue that topological insulator, semimetal and superconductor metamaterials are unique systems to bridge the missing links between nanophotonic, electronic, and spintronic technologies.
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Affiliation(s)
- Harish N S Krishnamoorthy
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonic Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Alexander M Dubrovkin
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonic Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Giorgio Adamo
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonic Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Cesare Soci
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonic Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
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7
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Yang H, Schmoranzerová E, Jang P, Nath J, Guillet T, Joumard I, Auffret S, Jamet M, Němec P, Gaudin G, Miron IM. Helicity dependent photoresistance measurement vs. beam-shift thermal gradient. Nat Commun 2022; 13:6790. [PMID: 36357377 PMCID: PMC9649656 DOI: 10.1038/s41467-022-34198-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 10/17/2022] [Indexed: 11/11/2022] Open
Abstract
Optical detection techniques are among the most powerful methods used to characterize spintronic phenomena. The spin orientation can affect the light polarization, which, by the reciprocal mechanism, can modify the spin density. Numerous recent experiments, report local changes in the spin density induced by a circularly polarized focused laser beam. These effects are typically probed electrically, by detecting the variations of the photoresistance or photocurrent associated to the reversal of the light helicity. Here we show that in general, when the light helicity is modified, the beam profile is slightly altered, and the barycenter of the laser spot is displaced. Consequently, the temperature gradients produced by the laser heating will be modulated, producing thermo-electric signals that alternate in phase with the light polarization. These unintended signals, having no connection with the electron spin, appear under the same experimental conditions and can be easily misinterpreted. We show how this contribution can be experimentally assessed and removed from the measured data. We find that even when the beam profile is optimized, this effect is large, and completely overshadows the spin related signals in all the materials and experimental conditions that we have tested. Many recent studies have explored the response of magnetic systems to circularly polarised light. To achieve this, typically experiments use a birefringent crystal. Here, Yang et al show that any small error in the alignment of the crystal can result in a beam shift, and this shift can lead to spurious signals similar yet unrelated to the electron spin.
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Kiemle J, Powalla L, Polyudov K, Gulati L, Singh M, Holleitner AW, Burghard M, Kastl C. Gate-Tunable Helical Currents in Commensurate Topological Insulator/Graphene Heterostructures. ACS NANO 2022; 16:12338-12344. [PMID: 35968692 DOI: 10.1021/acsnano.2c03370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
van der Waals heterostructures made from graphene and three-dimensional topological insulators promise very high electron mobilities, a nontrivial spin texture, and a gate-tunability of electronic properties. Such a combination of advantageous electronic characteristics can only be achieved through proximity effects in heterostructures, as graphene lacks a large enough spin-orbit interaction. In turn, the heterostructures are promising candidates for all-electrical control of proximity-induced spin phenomena. Here, we explore epitaxially grown interfaces between graphene and the lattice-matched topological insulator Bi2Te2Se. For this heterostructure, spin-orbit coupling proximity has been predicted to impart an anisotropic and electronically tunable spin texture. Polarization-resolved second-harmonic generation, Raman spectroscopy, and time-resolved magneto-optic Kerr microscopy are combined to demonstrate that the atomic interfaces align in a commensurate symmetry with characteristic interlayer vibrations. By polarization-resolved photocurrent measurements, we find a circular photogalvanic effect which is drastically enhanced at the Dirac point of the proximitized graphene. We attribute the peculiar gate-tunability to the proximity-induced interfacial spin structure, which could be exploited for, e.g., spin filters.
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Affiliation(s)
- Jonas Kiemle
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
| | - Lukas Powalla
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Katharina Polyudov
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Lovish Gulati
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Maanwinder Singh
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
| | - Alexander W Holleitner
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
| | - Marko Burghard
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Christoph Kastl
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
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9
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Incident Angle Dependence of the Waveform of the Polarization-Sensitive Photoresponse in CuSe/Se Thin Film. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12146869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The results of studying the waveforms of longitudinal and transverse photocurrent pulses generated in thin, semitransparent CuSe/Se films as a function of the angle of incidence (α) of a femtosecond laser beam at linear and circular polarizations are presented. It has been established that the durations of unipolar longitudinal photocurrent pulses at linear and circular polarizations of laser pumping do not depend on the angle α. It is shown that the evolution of the temporal profile of the helicity-sensitive transverse photocurrent with a change in α strongly depends on polarization. At linear polarization, the shape of the unipolar pulses remains virtually constant; however, at circular polarization, the generation of unipolar and bipolar pulses is possible, with the waveforms strongly depending on the angle α. The influence of the incidence angle on the waveforms of transverse photocurrent pulses is explained by the transformation of linear and circular polarization into an elliptical upon the refraction of light at the air/semitransparent film interface and by the interplay of photocurrents arising due to linear and circular surface photogalvanic effects in the film. The presented findings can be utilized to develop polarization and incidence angle-sensitive photovoltaic devices.
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10
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Roy S, Manna S, Mitra C, Pal B. Photothermal Control of Helicity-Dependent Current in Epitaxial Sb 2Te 2Se Topological Insulator Thin-Films at Ambient Temperature. ACS APPLIED MATERIALS & INTERFACES 2022; 14:9909-9916. [PMID: 35156377 DOI: 10.1021/acsami.1c24461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Optical control of helicity-dependent photocurrent in topological insulator (TI) Sb2Te2Se has been studied at room temperature on epitaxial thin-films grown by pulsed laser deposition (PLD). Comparison with a theoretical model, which fits the data very well, reveals different contributions to the measured photocurrent. Study of the dependence of photocurrent on the angle of incidence (wave-vector) of the excitation light with respect to the sample normal helps to identify the origin of different components of the photocurrent. Enhancement and inversion of the photocurrent in the presence of the photothermal gradient for light incident on two opposite edges of the sample occur due to selective spin-state excitation with two opposite circularly polarized lights in the presence of the unique spin-momentum locked surface states. These observations render the PLD-grown epitaxial TI thin-films promising for optoelectronic devices such as sensors, switches, and actuators whose response can be controlled by polarization as well as the angle of incidence of light under ambient conditions. The polarization response can also be tuned by the photothermal effect by suitably positioning the incident light beam on the device.
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Affiliation(s)
- Samrat Roy
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal 741246, India
| | - Subhadip Manna
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal 741246, India
| | - Chiranjib Mitra
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal 741246, India
| | - Bipul Pal
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal 741246, India
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11
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Liang G, Zhai G, Ma J, Wang H, Zhao J, Wu X, Zhang X. Strain-induced circular photogalvanic current in Dirac semimetal Cd 3As 2 films epitaxied on a GaAs(111)B substrate. NANOSCALE 2022; 14:2383-2392. [PMID: 35088779 DOI: 10.1039/d1nr05812f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Dirac semimetal (DSM) Cd3As2 has drawn great attention for exploring the novel quantum phenomena and high-speed optoelectronic applications. The circular photogalvanic effect (CPGE) current, resulting from the optically-excited spin orientation transport, was theoretically predicted to vanish in an ideal Dirac system due to the symmetric photoexcitation about the Dirac point. Here, we reported the observation of the CPGE photocurrent in epitaxial Cd3As2 thin films grown on a GaAs(111)B substrate. The signature of the CPGE is confirmed by its sign reversal upon switching the helicity of optical radiation, as well as its dependence on the excitation incident angle and power. By comparison of the CPGE response between the films with different thicknesses, it is suggested that the observed CPGE results from the reduced structure symmetry and substantially modified electronic band structure of the Cd3As2 thin film that undergoes large epitaxial strain. Our experimental findings provide a valuable reference for the band engineering and exotic helicity-dependent photocurrent phenomena in DSMs towards their potential opto-spintronic device applications.
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Affiliation(s)
- Gaoming Liang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Guihao Zhai
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jialin Ma
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Hailong Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xiaoguang Wu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xinhui Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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12
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Ma Q, Grushin AG, Burch KS. Topology and geometry under the nonlinear electromagnetic spotlight. NATURE MATERIALS 2021; 20:1601-1614. [PMID: 34127824 DOI: 10.1038/s41563-021-00992-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
For many materials, a precise knowledge of their dispersion spectra is insufficient to predict their ordered phases and physical responses. Instead, these materials are classified by the geometrical and topological properties of their wavefunctions. A key challenge is to identify and implement experiments that probe or control these quantum properties. In this Review, we describe recent progress in this direction, focusing on nonlinear electromagnetic responses that arise directly from quantum geometry and topology. We give an overview of the field by discussing theoretical ideas, experiments and the materials that drive them. We conclude by discussing how these techniques can be combined with device architectures to uncover, probe and ultimately control quantum phases with emergent topological and correlated properties.
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Affiliation(s)
- Qiong Ma
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Adolfo G Grushin
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, France
| | - Kenneth S Burch
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
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13
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Huang PJ, Taniguchi K, Shigefuji M, Kobayashi T, Matsubara M, Sasagawa T, Sato H, Miyasaka H. Chirality-Dependent Circular Photogalvanic Effect in Enantiomorphic 2D Organic-Inorganic Hybrid Perovskites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008611. [PMID: 33754374 DOI: 10.1002/adma.202008611] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/02/2021] [Indexed: 05/21/2023]
Abstract
The control of the optoelectronic properties of 2D organic-inorganic hybrid perovskite (2D-OIHP) lead halides is an increasingly prevalent topic. Herein, the observation of the circular photogalvanic effect (CPGE) in new enantiomorphic 2D-OIHP lead iodides is reported, which are synthesized as a first OIHP-related system belonging to a chiral space group by incorporating organic chiral cations into the inorganic layers of lead iodides. The CPGE is an optoelectronic phenomenon associated with the spin-orbit coupling of heavy atoms in noncentrosymmetric systems. Owing to the CPGE, light-helicity-dependent steady photocurrents are generated without an external bias voltage under the irradiation of circularly polarized light. Furthermore, the sign reversal of the CPGE photocurrent depending on the chirality of the designed 2D-OIHP lead iodides is observed. This result indicates formation of the theoretically predicted radial spin-polarized texture in k-space of chiral systems owing to spin-momentum locking. Hence, chiral 2D-OIHP lead halides can be a promising platform for engineering opto-spintronic functionalities.
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Affiliation(s)
- Po-Jung Huang
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Kouji Taniguchi
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
- PRESTO, Japan Science and Technology Agency (JST), 5-3 Yonbancho, Chiyoda-ku, Tokyo, 102-8666, Japan
| | - Masato Shigefuji
- Department of Physics, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Takatsugu Kobayashi
- Department of Physics, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Masakazu Matsubara
- Department of Physics, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Takao Sasagawa
- Laboratory for Materials and Structures (MSL), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
| | - Hiroyasu Sato
- Application Laboratories, Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima-shi, Tokyo, 196-8666, Japan
| | - Hitoshi Miyasaka
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
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14
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Sun X, Adamo G, Eginligil M, Krishnamoorthy HNS, Zheludev NI, Soci C. Topological insulator metamaterial with giant circular photogalvanic effect. SCIENCE ADVANCES 2021; 7:eabe5748. [PMID: 33811072 PMCID: PMC11057521 DOI: 10.1126/sciadv.abe5748] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
One of the most notable manifestations of electronic properties of topological insulators is the dependence of the photocurrent direction on the helicity of circularly polarized optical excitation. The helicity-dependent photocurrents, underpinned by spin-momentum locking of surface Dirac electrons, are weak and easily overshadowed by bulk contributions. Here, we show that the chiral response can be enhanced by nanostructuring. The tight confinement of electromagnetic fields in the resonant nanostructure enhances the photoexcitation of spin-polarized surface states of topological insulator Bi1.5Sb0.5Te1.8Se1.2, leading to an 11-fold increase of the circular photogalvanic effect and a previously unobserved photocurrent dichroism (ρcirc = 0.87) at room temperature. The control of spin transport in topological materials by structural design is a previously unrecognized ability of metamaterials that bridges the gap between nanophotonics and spin electronics, providing opportunities for developing polarization-sensitive photodetectors.
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Affiliation(s)
- X Sun
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - G Adamo
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - M Eginligil
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - H N S Krishnamoorthy
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
| | - N I Zheludev
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, UK
| | - C Soci
- Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore 637371, Singapore.
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore
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15
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Xie F, Lian Z, Zhang S, Wang T, Miao S, Song Z, Ying Z, Pan XC, Long M, Zhang M, Fei F, Hu W, Yu G, Song F, Kang TT, Shi SF. Reversible engineering of topological insulator surface state conductivity through optical excitation. NANOTECHNOLOGY 2021; 32:17LT01. [PMID: 33620033 DOI: 10.1088/1361-6528/abde01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Despite the broadband response, limited optical absorption at a particular wavelength hinders the development of optoelectronics based on Dirac fermions. Heterostructures of graphene and various semiconductors have been explored for this purpose, while non-ideal interfaces often limit the performance. The topological insulator (TI) is a natural hybrid system, with the surface states hosting high-mobility Dirac fermions and the small-bandgap semiconducting bulk state strongly absorbing light. In this work, we show a large photocurrent response from a field effect transistor device based on intrinsic TI Sn-Bi1.1Sb0.9Te2S (Sn-BSTS). The photocurrent response is non-volatile and sensitively depends on the initial Fermi energy of the surface state, and it can be erased by controlling the gate voltage. Our observations can be explained with a remote photo-doping mechanism, in which the light excites the defects in the bulk and frees the localized carriers to the surface state. This photodoping modulates the surface state conductivity without compromising the mobility, and it also significantly modify the quantum Hall effect of the surface state. Our work thus illustrates a route to reversibly manipulate the surface states through optical excitation, shedding light into utilizing topological surface states for quantum optoelectronics.
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Affiliation(s)
- Faji Xie
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
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16
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Sun R, Yang S, Yang X, Kumar A, Vetter E, Xue W, Li Y, Li N, Li Y, Zhang S, Ge B, Zhang XQ, He W, Kemper AF, Sun D, Cheng ZH. Visualizing Tailored Spin Phenomena in a Reduced-Dimensional Topological Superlattice. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2005315. [PMID: 33145825 DOI: 10.1002/adma.202005315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/27/2020] [Indexed: 06/11/2023]
Abstract
Emergent topological insulators (TIs) and their design are in high demand for manipulating and transmitting spin information toward ultralow-power-consumption spintronic applications. Here, distinct topological states with tailored spin properties can be achieved in a single reduced-dimensional TI-superlattice, (Bi2 /Bi2 Se3 )-(Bi2 /Bi2 Se3 )N or (□/Bi2 Se3 )-(Bi2 /Bi2 Se3 )N (N is the repeating unit, □ represents an empty layer) by controlling the termination via molecular beam epitaxy. The Bi2 -terminated superlattice exhibits a single Dirac cone with a spin momentum splitting ≈0.5 Å-1 , producing a pronounced inverse Edelstein effect with a coherence length up to 1.26 nm. In contrast, the Bi2 Se3 -terminated superlattice is identified as a dual TI protected by coexisting time reversal and mirror symmetries, showing an unexpectedly long spin lifetime up to 1 ns. The work elucidates the key role of dimensionality and dual topological phases in selecting desired spin properties, suggesting a promise route for engineering topological superlattices for high-performance TI-spintronic devices.
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Affiliation(s)
- Rui Sun
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shijia Yang
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Xu Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - A Kumar
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Eric Vetter
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Wenhua Xue
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yan Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Na Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shihao Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Binghui Ge
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Xiang-Qun Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wei He
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Alexander F Kemper
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Dali Sun
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
- Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA
| | - Zhao-Hua Cheng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
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17
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Deep tuning of photo-thermoelectricity in topological surface states. Sci Rep 2020; 10:16761. [PMID: 33028944 PMCID: PMC7541493 DOI: 10.1038/s41598-020-73950-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/22/2020] [Indexed: 11/08/2022] Open
Abstract
Three-dimensional topological insulators have been demonstrated in recent years, which possess intriguing gapless, spin-polarized Dirac states with linear dispersion only on the surface. The spin polarization of the topological surface states is also locked to its momentum, which allows controlling motion of electrons using optical helicity, i.e., circularly polarized light. The electrical and thermal transport can also be significantly tuned by the helicity-control of surface state electrons. Here, we report studies of photo-thermoelectric effect of the topological surface states in Bi2Te2Se thin films with large tunability using varied gate voltages and optical helicity. The Seebeck coefficient can be altered by more than five times compared to the case without spin injection. This deep tuning is originated from the optical helicity-induced photocurrent which is shown to be enhanced, reduced, turned off, and even inverted due to the change of the accessed band structures by electrical gating. The helicity-selected topological surface state thus has a large effect on thermoelectric transport, demonstrating great opportunities for realizing helicity control of optoelectronic and thermal devices.
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18
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Scattering symmetry-breaking induced spin photocurrent from out-of-plane spin texture in a 3D topological insulator. Sci Rep 2020; 10:10610. [PMID: 32606295 PMCID: PMC7327057 DOI: 10.1038/s41598-020-67612-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 06/01/2020] [Indexed: 12/02/2022] Open
Abstract
We theoretically study helicity-dependent photocurrent in a three-dimensional topological insulator Bi2Te3 under elastic scattering of different symmetries. By exploring spin-selective optical transitions and symmetry-breaking scattering, we are able to address the out-of-plane spin texture of the topological helical surface states and to generate directional, spin-polarization tunable photocurrent that is otherwise forbidden for the original C3v symmetry of the surface. This can be achieved regardless of the Fermi level, even under the condition when the topological states are inaccessible in dark. This work paves the way to robustly explore the out-of-plane spin texture for harvesting opto-spintronic functionalities of topological insulators.
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19
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Yu J, Xia L, Zhu K, Pan Q, Zeng X, Chen Y, Liu Y, Yin C, Cheng S, Lai Y, He K, Xue Q. Control of Circular Photogalvanic Effect of Surface States in the Topological Insulator Bi 2Te 3 via Spin Injection. ACS APPLIED MATERIALS & INTERFACES 2020; 12:18091-18100. [PMID: 32212669 DOI: 10.1021/acsami.9b23389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The circular photogalvanic effect (CPGE) provides a method utilizing circularly polarized light to control spin photocurrent and will also lead to novel opto-spintronic devices. The CPGE of three-dimensional topological insulator Bi2Te3 with different substrates and thicknesses has been systematically investigated. It is found that the CPGE current can be dramatically tuned by adopting different substrates. The CPGE current of the Bi2Te3 films on Si substrates are more than two orders larger than that on SrTiO3 substrates when illuminated by 1064 nm light, which can be attributed to the modulation effect due to the spin injection from Si substrate to Bi2Te3 films, larger light absorption coefficient, and stronger inequivalence between the top and bottom surface states for Bi2Te3 films grown on Si substrates. The excitation power dependence of the CPGE current of Bi2Te3 films on Si substrates shows a saturation at high power especially for thicker samples, whereas that on SrTiO3 substrates almost linearly increases with excitation power. Temperature dependence of the CPGE current of Bi2Te3 films on Si substrates first increases and then decreases with decreasing temperature, whereas that on SrTiO3 substrates changes monotonously with temperature. These interesting phenomena of the CPGE current of Bi2Te3 films on Si substrates are related to the spin injection from Si substrates to Bi2Te3 films. Our work not only intrigues new physics but also provides a method to effectively manipulate the helicity-dependent photocurrent via spin injection.
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Affiliation(s)
- Jinling Yu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
| | - Lijia Xia
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
| | - Kejing Zhu
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
| | - Qinggao Pan
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
| | - Xiaolin Zeng
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yonghai Chen
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Liu
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chunming Yin
- School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia
- CAS Key Laboratory of Microscale Magnetic Resonance, Department of Modern Physics, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Shuying Cheng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
- Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu ,China
| | - Yunfeng Lai
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China
| | - Ke He
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
| | - Qikun Xue
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
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20
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Zonov RG, Mikheev GM, Obraztsov AN, Svirko YP. Circular photocurrent in the carbon nanowall film. OPTICS LETTERS 2020; 45:2022-2025. [PMID: 32236058 DOI: 10.1364/ol.391528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 02/29/2020] [Indexed: 06/11/2023]
Abstract
We report the helicity-dependent photocurrent in the carbon nanowall film synthesized on the silicon substrates by the chemical vapor deposition technique. The film is composed of multilayer graphene flakes grown along the substrate normal. We measured the transverse photocurrent generated in the film under irradiation with nanosecond laser pulses by depositing two conductive electrodes along the plane of incidence. The measurements were performed by using elliptically polarized fundamental, second-, third-, and fourth-harmonics beams of the Nd:YAG laser. We revealed that the shorter the excitation wavelength, the higher the magnitude of the helicity-dependent transverse photocurrent generated in the film. In particular, at wavelengths of 266 and 355 nm, the photocurrent strongly depends on the degree of the circular polarization of the laser beam while, at the wavelength of 1064 nm, the transverse photocurrent is almost helicity independent.
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21
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Osterhoudt GB, Diebel LK, Gray MJ, Yang X, Stanco J, Huang X, Shen B, Ni N, Moll PJW, Ran Y, Burch KS. Colossal mid-infrared bulk photovoltaic effect in a type-I Weyl semimetal. NATURE MATERIALS 2019; 18:471-475. [PMID: 30833781 DOI: 10.1038/s41563-019-0297-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
Broadband, efficient and fast conversion of light to electricity is crucial for sensing and clean energy. The bulk photovoltaic effect (BPVE) is a second-order nonlinear optical effect that intrinsically converts light into electrical current. Here, we demonstrate a large mid-infrared BPVE in microscopic devices of the Weyl semimetal TaAs. This discovery results from combining recent developments in Weyl semimetals, focused-ion beam fabrication and theoretical works suggesting a connection between BPVE and topology. We also present a detailed symmetry analysis that allows us to separate the shift current response from photothermal effects. The magnitude and wavelength range of the assigned shift current may impact optical detectors, clean energy and topology, and demonstrate the utility of Weyl semimetals for practical applications.
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Affiliation(s)
| | - Laura K Diebel
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Mason J Gray
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Xu Yang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - John Stanco
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Xiangwei Huang
- Max-Planck-Institute for Chemical Physics of Solids, Dresden, Germany
| | - Bing Shen
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Ni Ni
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Philip J W Moll
- Max-Planck-Institute for Chemical Physics of Solids, Dresden, Germany
- EPFL, IMX, Lausanne, Switzerland
| | - Ying Ran
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Kenneth S Burch
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
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22
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Soifer H, Gauthier A, Kemper AF, Rotundu CR, Yang SL, Xiong H, Lu D, Hashimoto M, Kirchmann PS, Sobota JA, Shen ZX. Band-Resolved Imaging of Photocurrent in a Topological Insulator. PHYSICAL REVIEW LETTERS 2019; 122:167401. [PMID: 31075004 DOI: 10.1103/physrevlett.122.167401] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 02/05/2019] [Indexed: 06/09/2023]
Abstract
We study the microscopic origins of photocurrent generation in the topological insulator Bi_{2}Se_{3} via time- and angle-resolved photoemission spectroscopy. We image the unoccupied band structure as it evolves following a circularly polarized optical excitation and observe an asymmetric electron population in momentum space, which is the spectroscopic signature of a photocurrent. By analyzing the rise times of the population we identify which occupied and unoccupied electronic states are coupled by the optical excitation. We conclude that photocurrents can only be excited via resonant optical transitions coupling to spin-orbital textured states. Our work provides a microscopic understanding of how to control photocurrents in systems with spin-orbit coupling and broken inversion symmetry.
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Affiliation(s)
- H Soifer
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - A Gauthier
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | - A F Kemper
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - C R Rotundu
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - S-L Yang
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | - H Xiong
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | - D Lu
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - M Hashimoto
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - P S Kirchmann
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - J A Sobota
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Z-X Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
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23
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Seifert P, Kundinger M, Shi G, He X, Wu K, Li Y, Holleitner A, Kastl C. Quantized Conductance in Topological Insulators Revealed by the Shockley-Ramo Theorem. PHYSICAL REVIEW LETTERS 2019; 122:146804. [PMID: 31050462 DOI: 10.1103/physrevlett.122.146804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 02/14/2019] [Indexed: 06/09/2023]
Abstract
Crystals with symmetry-protected topological order, such as topological insulators, promise coherent spin and charge transport phenomena even in the presence of disorder at room temperature. We demonstrate how to image and read out the local conductance of helical surface modes in the prototypical topological insulators Bi_{2}Se_{3} and BiSbTe_{3}. We apply the so-called Shockley-Ramo theorem to design an optoelectronic probe circuit for the gapless surface states, and we find a well-defined conductance quantization at 1e^{2}/h within the experimental error without any external magnetic field. The unprecedented response is a clear signature of local spin-polarized transport, and it can be switched on and off via an electrostatic field effect. The macroscopic, global readout scheme is based on an electrostatic coupling from the local excitation spot to the readout electrodes, and it does not require coherent transport between electrodes, in contrast to the conventional Landauer-Büttiker description. It provides a generalizable platform for studying further nontrivial gapless systems such as Weyl semimetals and quantum spin-Hall insulators.
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Affiliation(s)
- Paul Seifert
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
| | - Marinus Kundinger
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
| | - Gang Shi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoyue He
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Kehui Wu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yongqing Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Alexander Holleitner
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
| | - Christoph Kastl
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
- Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
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Temperature-Dependent Raman Scattering of Large Size Hexagonal Bi2Se3 Single-Crystal Nanoplates. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8101794] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bi 2 Se 3 has extensive application as thermoelectric materials. Here, large-scale Bi 2 Se 3 single-crystal hexagonal nanoplates with size 7.50–10.0 μ m were synthesized successfully by hydrothermal method. X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to characterize the Bi 2 Se 3 nanoplates, which confirm the single-crystal quality and smooth surface morphology with large size. Micro-Raman spectra over a temperature range of 83–603 K were furthermore used to investigate the lattice dynamics of Bi 2 Se 3 nanoplates. Both 2A g 1 and 1E g 2 modes shift evidently with reduced temperature. The line shape demonstrates a significant broadening of full width at half maximum (FWHM) and red-shift of frequency with increased temperature. The temperature coefficient of A 1 g 1 , E g 2 , A 1 g 2 modes were determined to be −1.258 × 10 − 2 cm − 1 /K, −1.385 × 10 − 2 cm − 1 /K, −2.363 × 10 − 2 cm − 1 /K, respectively. Such low temperature coefficient may favor the obtaining of a high figure of merit (ZT) and indicate that Bi 2 Se 3 nanoplates were used as excellent candidates of thermoelectric materials.
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25
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Luo S, He L, Li M. Spin-momentum locked interaction between guided photons and surface electrons in topological insulators. Nat Commun 2017; 8:2141. [PMID: 29247165 PMCID: PMC5732163 DOI: 10.1038/s41467-017-02264-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/16/2017] [Indexed: 11/16/2022] Open
Abstract
The propagation of electrons and photons can respectively have the spin-momentum locking effect which correlates spin with linear momentum. For surface electrons in three-dimensional topological insulators (TIs), their spin is locked to the transport direction. Analogously, photons in optical waveguides carry transverse spin angular momentum which is also locked to the propagation direction. A direct connection between electron and photon spins occurs in TIs due to spin-dependent selection rules of optical transitions. Here we demonstrate an optoelectronic device that integrates a TI with a photonic waveguide. Interaction between photons in the waveguide and surface electrons in a Bi2Se3 layer generates a directional, spin-polarized photocurrent. Because of spin-momentum locking, changing light propagation direction reverses photon spin and thus the direction of the photocurrent. Our device represents a way of implementing coupled spin–orbit interaction between electrons and photons and may lead to applications in opto-spintronics and quantum information processing. Whether topologically protected electron moving and photon moving can couple each other remains an interesting question. Here, Luo et al. report reversion of photon spin and the direction of the photocurrent in a topological insulator by changing light propagation direction.
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Affiliation(s)
- Siyuan Luo
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.,Institute of Fundamental and Frontier Sciences, State Key Laboratory of Electronics Thin Films and Integrated Devices, University of Electronics Science and Technology of China, Chengdu, 610054, China
| | - Li He
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.,School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Mo Li
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.
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