1
|
Shan M, Li S, Yang Y, Zhao D, Li J, Nie L, Wu Z, Zhou Y, Zheng L, Kang B, Wu T, Chen X. Anisotropic Spin Fluctuations Induced by Spin-Orbit Coupling in a Misfit Layer Compound (LaSe) 1.14(NbSe 2). ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403824. [PMID: 39206691 DOI: 10.1002/advs.202403824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 08/02/2024] [Indexed: 09/04/2024]
Abstract
Spin-orbit coupling (SOC) has significant effects on the superconductivity and magnetism of transition metal dichalcogenides (TMDs) at the 2D limit. Although 2D TMD samples possess many exotic properties different from those of bulk samples, experimental characterization in this field is still limited, especially for magnetism. Recent studies have revealed that bulk misfit layer compounds (MLCs) with (LaSe)1.14(NbSe2)n = 1,2 exhibit an Ising superconductivity similar to that of heavily electron-doped NbSe2 monolayers. This offers an opportunity to study the effect of SOC on the magnetism of 2D TMDs. Here, the possible SOC effect in (LaSe)1.14(NbSe2) is investigated by measuring nuclear magnetic resonance (NMR) and electrical transport. It is found that the LaSe layer not only functions as a charge reservoir for transferring electrons into the NbSe2 layer but also remarkably influences the local electronic environment around the 93Nb nuclei. More importantly, the significant SOC induces both a weak antilocalization (WAL) effect and anisotropic spin fluctuations in noncentrosymmetric NbSe2 layers. The present work contributes to a deep understanding of the role of the SOC effect in 2D TMDs and supports MCLs as an intriguing platform for exploring exotic physical properties within the 2D limit.
Collapse
Affiliation(s)
- Min Shan
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Shunjiao Li
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Ye Yang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Dan Zhao
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Jian Li
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Linpeng Nie
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Zhimian Wu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yanbing Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Lixuan Zheng
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Baolei Kang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Tao Wu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088, China
| | - Xianhui Chen
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088, China
| |
Collapse
|
2
|
Joe AY, Pistunova K, Kaasbjerg K, Wang K, Kim B, Rhodes DA, Taniguchi T, Watanabe K, Hone J, Low T, Jauregui LA, Kim P. Transport Study of Charge-Carrier Scattering in Monolayer WSe_{2}. PHYSICAL REVIEW LETTERS 2024; 132:056303. [PMID: 38364168 DOI: 10.1103/physrevlett.132.056303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/04/2023] [Accepted: 12/20/2023] [Indexed: 02/18/2024]
Abstract
Employing flux-grown single crystal WSe_{2}, we report charge-carrier scattering behaviors measured in h-BN encapsulated monolayer field effect transistors. We observe a nonmonotonic change of transport mobility as a function of hole density in the degenerately doped sample, which can be explained by energy dependent scattering amplitude of strong defects calculated using the T-matrix approximation. Utilizing long mean-free path (>500 nm), we also demonstrate the high quality of our electronic devices by showing quantized conductance steps from an electrostatically defined quantum point contact, showing the potential for creating ultrahigh quality quantum optoelectronic devices based on atomically thin semiconductors.
Collapse
Affiliation(s)
- Andrew Y Joe
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Kateryna Pistunova
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | - Ke Wang
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Bumho Kim
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | - Daniel A Rhodes
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | | | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | - Tony Low
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Luis A Jauregui
- Department of Physics and Astronomy, The University of California, Irvine, California 92697, USA
| | - Philip Kim
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| |
Collapse
|
3
|
Sheoran S, Monga S, Phutela A, Bhattacharya S. Coupled Spin-Valley, Rashba Effect, and Hidden Spin Polarization in WSi 2N 4 Family. J Phys Chem Lett 2023; 14:1494-1503. [PMID: 36745045 DOI: 10.1021/acs.jpclett.2c03108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Using first-principles calculations, we report the electronic properties with a special focus on the band splitting in the WSi2N4 class of materials. Due to the broken inversion symmetry and strong spin-orbit coupling, we detect coupled spin-valley effects at the corners of the first Brillouin zone (BZ). Additionally, we observe cubically and linearly split bands around the Γ and M points, respectively. The in-plane mirror symmetry (σh) and reduced symmetry of the arbitrary k-point, enforce the persistent spin textures (PST) to occur in full BZ. We induce the Rashba splitting by breaking the σh through an out-of-plane external electric field (EEF). The inversion asymmetric site point group of the W atom introduces the hidden spin polarization in centrosymmetric layered bulk counterparts. Low energy k.p models demonstrate that the PST along the M-K line is robust to EEF and layer thickness, making them suitable for applications in spintronics and valleytronics.
Collapse
Affiliation(s)
- Sajjan Sheoran
- Department of Physics, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Sanchi Monga
- Department of Physics, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Ankita Phutela
- Department of Physics, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Saswata Bhattacharya
- Department of Physics, Indian Institute of Technology Delhi, New Delhi, 110016, India
| |
Collapse
|
4
|
Liu T, Xiang D, Ng HK, Han Z, Hippalgaonkar K, Suwardi A, Martin J, Garaj S, Wu J. Modulation of Spin Dynamics in 2D Transition-Metal Dichalcogenide via Strain-Driven Symmetry Breaking. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2200816. [PMID: 35491496 PMCID: PMC9284128 DOI: 10.1002/advs.202200816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/21/2022] [Indexed: 06/14/2023]
Abstract
Transition metal dichalcogenides (TMDs) possess intrinsic spin-orbit interaction (SOI) with high potential to be exploited for various quantum phenomena. SOI allows the manipulation of spin degree of freedom by controlling the carrier's orbital motion via mechanical strain. Here, strain modulated spin dynamics in bilayer MoS2 field-effect transistors (FETs) fabricated on crested substrates are demonstrated. Weak antilocalization (WAL) is observed at moderate carrier concentrations, indicating additional spin relaxation path caused by strain fields arising from substrate crests. The spin lifetime is found to be inversely proportional to the momentum relaxation time, which follows the Dyakonov-Perel spin relaxation mechanism. Moreover, the spin-orbit splitting is obtained as 37.5 ± 1.4 meV, an order of magnitude larger than the theoretical prediction for monolayer MoS2 , suggesting the strain enhanced spin-lattice coupling. The work demonstrates strain engineering as a promising approach to manipulate spin degree of freedom toward new functional quantum devices.
Collapse
Affiliation(s)
- Tao Liu
- Institute of Optoelectronics & Zhangjiang Fudan International Innovation CenterFudan UniversityShanghai200438China
| | - Du Xiang
- Frontier Institute of Chip and System & Zhangjiang Fudan International Innovation CenterFudan UniversityShanghai200438China
| | - Hong Kuan Ng
- Institute of Materials Research and EngineeringAgency for Science, Technology and Research2 Fusionopolis Way, Innovis, #08‐03Singapore138634Singapore
| | - Zichao Han
- Institute of Optoelectronics & Zhangjiang Fudan International Innovation CenterFudan UniversityShanghai200438China
| | - Kedar Hippalgaonkar
- Institute of Materials Research and EngineeringAgency for Science, Technology and Research2 Fusionopolis Way, Innovis, #08‐03Singapore138634Singapore
- Department of Materials Science and EngineeringNanyang Technological UniversitySingapore639798Singapore
| | - Ady Suwardi
- Institute of Materials Research and EngineeringAgency for Science, Technology and Research2 Fusionopolis Way, Innovis, #08‐03Singapore138634Singapore
- Department of Materials Science and EngineeringNational University of Singapore9 Engineering Drive 1SingaporeSingapore117575Singapore
| | - Jens Martin
- Leibniz‐Institut für KristallzüchtungMax Born Str 2Berlin12489Germany
| | - Slaven Garaj
- Department of PhysicsNational University of Singapore, SingaporeScience Drive 3Singapore117551Singapore
- Department of Biomedical EngineeringNational University of Singapore4 Engineering Drive 3Singapore117583Singapore
- Department of Materials Science and EngineeringNational University of Singapore9 Engineering Drive 1SingaporeSingapore117575Singapore
| | - Jing Wu
- Institute of Materials Research and EngineeringAgency for Science, Technology and Research2 Fusionopolis Way, Innovis, #08‐03Singapore138634Singapore
- Department of Materials Science and EngineeringNational University of Singapore9 Engineering Drive 1SingaporeSingapore117575Singapore
| |
Collapse
|
5
|
Islam S, Shamim S, Ghosh A. Benchmarking Noise and Dephasing in Emerging Electrical Materials for Quantum Technologies. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2109671. [PMID: 35545231 DOI: 10.1002/adma.202109671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 05/01/2022] [Indexed: 06/15/2023]
Abstract
As quantum technologies develop, a specific class of electrically conducting materials is rapidly gaining interest because they not only form the core quantum-enabled elements in superconducting qubits, semiconductor nanostructures, or sensing devices, but also the peripheral circuitry. The phase coherence of the electronic wave function in these emerging materials will be crucial when incorporated in the quantum architecture. The loss of phase memory, or dephasing, occurs when a quantum system interacts with the fluctuations in the local electromagnetic environment, which manifests in "noise" in the electrical conductivity. Hence, characterizing these materials and devices therefrom, for quantum applications, requires evaluation of both dephasing and noise, although there are very few materials where these properties are investigated simultaneously. Here, the available data on magnetotransport and low-frequency fluctuations in electrical conductivity are reviewed to benchmark the dephasing and noise. The focus is on new materials that are of direct interest to quantum technologies. The physical processes causing dephasing and noise in these systems are elaborated, the impact of both intrinsic and extrinsic parameters from materials synthesis and devices realization are evaluated, and it is hoped that a clearer pathway to design and characterize both material and devices for quantum applications is thus provided.
Collapse
Affiliation(s)
- Saurav Islam
- Department of Physics, Indian Institute of Science, Bengaluru, 560012, India
| | - Saquib Shamim
- Experimentelle Physik III, Physikalisches Institut, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Topological Insulators, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Arindam Ghosh
- Department of Physics, Indian Institute of Science, Bengaluru, 560012, India
- Centre for Nano Science and Engineering, Indian Institute of Science, Bengaluru, 560012, India
| |
Collapse
|
6
|
Pal A, Zhang S, Chavan T, Agashiwala K, Yeh CH, Cao W, Banerjee K. Quantum-Engineered Devices Based on 2D Materials for Next-Generation Information Processing and Storage. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2109894. [PMID: 35468661 DOI: 10.1002/adma.202109894] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 04/11/2022] [Indexed: 06/14/2023]
Abstract
As an approximation to the quantum state of solids, the band theory, developed nearly seven decades ago, fostered the advance of modern integrated solid-state electronics, one of the most successful technologies in the history of human civilization. Nonetheless, their rapidly growing energy consumption and accompanied environmental issues call for more energy-efficient electronics and optoelectronics, which necessitate the exploration of more advanced quantum mechanical effects, such as band-to-band tunneling, spin-orbit coupling, spin-valley locking, and quantum entanglement. The emerging 2D layered materials, featured by their exotic electrical, magnetic, optical, and structural properties, provide a revolutionary low-dimensional and manufacture-friendly platform (and many more opportunities) to implement these quantum-engineered devices, compared to the traditional electronic materials system. Here, the progress in quantum-engineered devices is reviewed and the opportunities/challenges of exploiting 2D materials are analyzed to highlight their unique quantum properties that enable novel energy-efficient devices, and useful insights to quantum device engineers and 2D-material scientists are provided.
Collapse
Affiliation(s)
- Arnab Pal
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Shuo Zhang
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- College of ISEE, Zhejiang University, Hangzhou, 310027, China
| | - Tanmay Chavan
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kunjesh Agashiwala
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Chao-Hui Yeh
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Wei Cao
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kaustav Banerjee
- ECE Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| |
Collapse
|
7
|
Zhang Y, Xue F, Tang C, Li J, Liao L, Li L, Liu X, Yang Y, Song C, Kou X. Highly Efficient Electric-Field Control of Giant Rashba Spin-Orbit Coupling in Lattice-Matched InSb/CdTe Heterostructures. ACS NANO 2020; 14:17396-17404. [PMID: 33301682 DOI: 10.1021/acsnano.0c07598] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Spin-orbit coupling (SOC), the relativistic effect describing the interaction between the orbital and spin degrees of freedom, provides an effective way to tailor the spin/magnetic orders using electrical means. Here, we report the manipulation of the spin-orbit interaction in the lattice-matched InSb/CdTe heterostructures. Owing to the energy band bending at the heterointerface, the strong Rashba effect is introduced to drive the spin precession where pronounced weak antilocalization cusps are observed up to 100 K. With effective quantum confinement and suppressed bulk conduction, the SOC strength is found to be enhanced by 75% in the ultrathin InSb/CdTe film. Most importantly, we realize the electric-field control of the interfacial Rashba effect using a field-effect transistor structure and demonstrate the gate-tuning capability which is 1-2 orders of magnitude higher than other materials. The adoption of the InSb/CdTe integration strategy may set up a general framework for the design of strongly spin-orbit coupled systems that are essential for CMOS-compatible low-power spintronics.
Collapse
Affiliation(s)
- Yong Zhang
- School of Information Science and Technology, ShanghaiTech University, Shanghai 200031, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Fenghua Xue
- School of Information Science and Technology, ShanghaiTech University, Shanghai 200031, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Chenjia Tang
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 200031, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Jiaming Li
- School of Information Science and Technology, ShanghaiTech University, Shanghai 200031, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Liyang Liao
- Key Lab Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Lun Li
- School of Information Science and Technology, ShanghaiTech University, Shanghai 200031, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Xiaoyang Liu
- School of Information Science and Technology, ShanghaiTech University, Shanghai 200031, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Yumeng Yang
- School of Information Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Cheng Song
- Key Lab Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Xufeng Kou
- School of Information Science and Technology, ShanghaiTech University, Shanghai 200031, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 200031, China
| |
Collapse
|
8
|
Nakamura H, Huang D, Merz J, Khalaf E, Ostrovsky P, Yaresko A, Samal D, Takagi H. Robust weak antilocalization due to spin-orbital entanglement in Dirac material Sr 3SnO. Nat Commun 2020; 11:1161. [PMID: 32127524 PMCID: PMC7054336 DOI: 10.1038/s41467-020-14900-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 02/11/2020] [Indexed: 11/17/2022] Open
Abstract
The presence of both inversion (P) and time-reversal (T) symmetries in solids leads to a double degeneracy of the electronic bands (Kramers degeneracy). By lifting the degeneracy, spin textures manifest themselves in momentum space, as in topological insulators or in strong Rashba materials. The existence of spin textures with Kramers degeneracy, however, is difficult to observe directly. Here, we use quantum interference measurements to provide evidence for the existence of hidden entanglement between spin and momentum in the antiperovskite-type Dirac material Sr3SnO. We find robust weak antilocalization (WAL) independent of the position of EF. The observed WAL is fitted using a single interference channel at low doping, which implies that the different Dirac valleys are mixed by disorder. Notably, this mixing does not suppress WAL, suggesting contrasting interference physics compared to graphene. We identify scattering among axially spin-momentum locked states as a key process that leads to a spin-orbital entanglement.
Collapse
Affiliation(s)
- H Nakamura
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany.
- Department of Physics, University of Arkansas, Fayetteville, AR, 72701, USA.
| | - D Huang
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
| | - J Merz
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
| | - E Khalaf
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - P Ostrovsky
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
- L. D. Landau Institute for Theoretical Physics RAS, 119334, Moscow, Russia
| | - A Yaresko
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
| | - D Samal
- Institute of Physics, Bhubaneswar, 751005, India
- Homi Bhabha National Institute, Mumbai, 400085, India
| | - H Takagi
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
- Department of Physics, University of Tokyo, 113-0033, Tokyo, Japan
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569, Stuttgart, Germany
| |
Collapse
|
9
|
Liu H, Bao L, Zhou Z, Che B, Zhang R, Bian C, Ma R, Wu L, Yang H, Li J, Gu C, Shen CM, Du S, Gao HJ. Quasi-2D Transport and Weak Antilocalization Effect in Few-layered VSe 2. NANO LETTERS 2019; 19:4551-4559. [PMID: 31241975 DOI: 10.1021/acs.nanolett.9b01412] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
With strong spin-orbit coupling (SOC), ultrathin two-dimensional (2D) transitional metal chalcogenides (TMDs) are predicted to exhibit weak antilocalization (WAL) effect at low temperatures. The observation of WAL effect in VSe2 is challenging due to the relative weak SOC and three-dimensional (3D) transport nature in thick VSe2. Here, we report on the observation of quasi-2D transport and WAL effect in sublimed-salt-assisted low-temperature chemical vapor deposition (CVD) grown few-layered high-quality VSe2 nanosheets. The WAL magnitudes in magnetoconductance can be perfectly fitted by the 2D Hikami-Larkin-Nagaoka (HLN) equation in the presence of strong SOC, by which the spin-orbit scattering length lSO and phase coherence length lϕ have been extracted. The phase coherence length lϕ shows a power law dependence with temperature, lϕ∼ T-1/2, revealing an electron-electron interaction-dominated dephasing mechanism. Such sublimed-salt-assisted growth of high-quality few-layered VSe2 and the observation of WAL pave the way for future spintronic and valleytronic applications.
Collapse
Affiliation(s)
- Hongtao Liu
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Lihong Bao
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , P. R. China
| | - Zhang Zhou
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Bingyu Che
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Ruizi Zhang
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Ce Bian
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Ruisong Ma
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Liangmei Wu
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Haifang Yang
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Junjie Li
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Changzhi Gu
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| | - Cheng-Min Shen
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , P. R. China
| | - Shixuan Du
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , P. R. China
| | - Hong-Jun Gao
- Institute of Physics & University of Chinese Academy of Sciences , Chinese Academy of Sciences, Beijing , 100190 , P. R. China
| |
Collapse
|
10
|
Ye J, Li Y, Yan T, Zhai G, Zhang X. Ultrafast Dynamics of Spin Generation and Relaxation in Layered WSe 2. J Phys Chem Lett 2019; 10:2963-2970. [PMID: 31084014 DOI: 10.1021/acs.jpclett.9b01068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We investigated the build-up and relaxation processes of spin-polarized A- and B-exciton dynamics in monolayer, bilayer, and bulk WSe2 using helicity-resolved two-color pump-probe spectroscopy. Substantial spin polarization was confirmed in bulk crystals, though the spin polarization degree of A excitons decreased from monolayer to bulk. However, the spin polarization of A excitons almost vanished in all different layered-flakes when resonantly pumping the B-exciton transition, owing to the dominant role of interexciton transfer. When resonantly pumping the A-exciton transition, the spin polarization of the up-converted B excitons was inverted in all layers because of the efficient Dexter-like coupling and phonon-assisted scattering. The same short spin relaxation time (1.8 ± 0.2 ps) of A excitons was found for all studied flakes in the subsequent spin depolarization processes, which was ascribed to the active electron-phonon scattering resulting from the intrinsic small conduction-band spin-orbit coupling splitting in layered WSe2.
Collapse
Affiliation(s)
- Jialiang Ye
- 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
| | - Ying Li
- 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
| | - Tengfei Yan
- State Key Laboratory of Superlattices and Microstructures , Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083 , 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
| | - 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
| |
Collapse
|
11
|
Meng M, Huang S, Tan C, Wu J, Li X, Peng H, Xu HQ. Universal conductance fluctuations and phase-coherent transport in a semiconductor Bi 2O 2Se nanoplate with strong spin-orbit interaction. NANOSCALE 2019; 11:10622-10628. [PMID: 31139797 DOI: 10.1039/c9nr02347j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report on phase-coherent transport studies of a Bi2O2Se nanoplate and on observation of universal conductance fluctuations and spin-orbit interaction induced reduction in fluctuation amplitude in the nanoplate. Thin-layered Bi2O2Se nanoplates are grown by chemical vapor deposition (CVD) and transport measurements are made on a Hall-bar device fabricated from a CVD-grown nanoplate. The measurements show weak antilocalization at low magnetic fields at low temperatures, as a result of spin-orbit interaction, and a crossover toward weak localization with increasing temperature. Temperature dependences of characteristic transport lengths, such as spin relaxation length, phase coherence length, and mean free path, are extracted from the low-field measurement data. Universal conductance fluctuations are visible in the low-temperature magnetoconductance over a large range of magnetic fields and the phase coherence length extracted from the autocorrelation function is consistent with the result obtained from the weak localization analysis. More importantly, we find a strong reduction in amplitude of the universal conductance fluctuations and show that the results agree with the analysis assuming strong spin-orbit interaction in the Bi2O2Se nanoplate.
Collapse
Affiliation(s)
- Mengmeng Meng
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China.
| | | | | | | | | | | | | |
Collapse
|
12
|
Premasiri K, Gao XPA. Tuning spin-orbit coupling in 2D materials for spintronics: a topical review. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:193001. [PMID: 30726777 DOI: 10.1088/1361-648x/ab04c7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Atomically-thin 2D materials have opened up new opportunities in the past decade in realizing novel electronic device concepts, owing to their unusual electronic properties. The recent progress made in the aspect of utilizing additional degrees of freedom of the electrons such as spin and valley suggests that 2D materials have a significant potential in replacing current electronic-charge-based semiconductor technology with spintronics and valleytronics. For spintronics, spin-orbit coupling plays a key role in manipulating the electrons' spin degree of freedom to encode and process information, and there are a host of recent studies exploring this facet of 2D materials. We review the recent advances in tuning spin-orbit coupling of 2D materials which are of notable importance to the progression of spintronics.
Collapse
Affiliation(s)
- Kasun Premasiri
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, OH 44106, United States of America
| | | |
Collapse
|
13
|
Wang Z, Molina-Sánchez A, Altmann P, Sangalli D, De Fazio D, Soavi G, Sassi U, Bottegoni F, Ciccacci F, Finazzi M, Wirtz L, Ferrari AC, Marini A, Cerullo G, Dal Conte S. Intravalley Spin-Flip Relaxation Dynamics in Single-Layer WS 2. NANO LETTERS 2018; 18:6882-6891. [PMID: 30264571 DOI: 10.1021/acs.nanolett.8b02774] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In monolayer (1L) transition metal dichalcogenides (TMDs) the valence and conduction bands are spin-split because of the strong spin-orbit interaction. In tungsten-based TMDs the spin-ordering of the conduction band is such that the so-called dark excitons, consisting of electrons and holes with opposite spin orientation, have lower energy than A excitons. The transition from bright to dark excitons involves the scattering of electrons from the upper to the lower conduction band at the K point of the Brillouin zone, with detrimental effects for the optoelectronic response of 1L-TMDs, since this reduces their light emission efficiency. Here, we exploit the valley selective optical selection rules and use two-color helicity-resolved pump-probe spectroscopy to directly measure the intravalley spin-flip relaxation dynamics in 1L-WS2. This occurs on a sub-ps time scale, and it is significantly dependent on temperature, indicative of phonon-assisted relaxation. Time-dependent ab initio calculations show that intravalley spin-flip scattering occurs on significantly longer time scales only at the K point, while the occupation of states away from the minimum of the conduction band significantly reduces the scattering time. Our results shed light on the scattering processes determining the light emission efficiency in optoelectronic and photonic devices based on 1L-TMDs.
Collapse
Affiliation(s)
- Zilong Wang
- Department of Physics , Politecnico di Milano , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
| | - Alejandro Molina-Sánchez
- Institute of Materials Science (ICMUV) , University of Valencia , Catedrático Beltrán 2 , E-46980 Valencia , Spain
| | - Patrick Altmann
- Department of Physics , Politecnico di Milano , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
| | - Davide Sangalli
- CNR-ISM, Division of Ultrafast Process in Materials (FLASHit) , Area della Ricerca di Roma 1 , Monterotondo Scalo , Italy
| | - Domenico De Fazio
- Cambridge Graphene Centre , University of Cambridge , 9 JJ Thomson Avenue , Cambridge CB3 0FA , U.K
| | - Giancarlo Soavi
- Cambridge Graphene Centre , University of Cambridge , 9 JJ Thomson Avenue , Cambridge CB3 0FA , U.K
| | - Ugo Sassi
- Cambridge Graphene Centre , University of Cambridge , 9 JJ Thomson Avenue , Cambridge CB3 0FA , U.K
| | - Federico Bottegoni
- Department of Physics , Politecnico di Milano , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
| | - Franco Ciccacci
- Department of Physics , Politecnico di Milano , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
| | - Marco Finazzi
- Department of Physics , Politecnico di Milano , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
| | - Ludger Wirtz
- Université du Luxembourg , 162 A, avenue de la Faencerie , Luxembourg City L-1511 , Luxembourg
| | - Andrea C Ferrari
- Cambridge Graphene Centre , University of Cambridge , 9 JJ Thomson Avenue , Cambridge CB3 0FA , U.K
| | - Andrea Marini
- CNR-ISM, Division of Ultrafast Process in Materials (FLASHit) , Area della Ricerca di Roma 1 , Monterotondo Scalo , Italy
| | - Giulio Cerullo
- Department of Physics , Politecnico di Milano , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
- IFN-CNR , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
| | - Stefano Dal Conte
- Department of Physics , Politecnico di Milano , Piazza Leonardo da Vinci 32 , I-20133 Milano , Italy
| |
Collapse
|
14
|
Song K, Soriano D, Cummings AW, Robles R, Ordejón P, Roche S. Spin Proximity Effects in Graphene/Topological Insulator Heterostructures. NANO LETTERS 2018; 18:2033-2039. [PMID: 29481087 DOI: 10.1021/acs.nanolett.7b05482] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Enhancing the spin-orbit interaction in graphene, via proximity effects with topological insulators, could create a novel 2D system that combines nontrivial spin textures with high electron mobility. To engineer practical spintronics applications with such graphene/topological insulator (Gr/TI) heterostructures, an understanding of the hybrid spin-dependent properties is essential. However, to date, despite the large number of experimental studies on Gr/TI heterostructures reporting a great variety of remarkable (spin) transport phenomena, little is known about the true nature of the spin texture of the interface states as well as their role on the measured properties. Here, we use ab initio simulations and tight-binding models to determine the precise spin texture of electronic states in graphene interfaced with a Bi2Se3 topological insulator. Our calculations predict the emergence of a giant spin lifetime anisotropy in the graphene layer, which should be a measurable hallmark of spin transport in Gr/TI heterostructures and suggest novel types of spin devices.
Collapse
Affiliation(s)
- Kenan Song
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and BIST , Campus UAB , 08193 Barcelona , Spain
| | - David Soriano
- QuantaLab & International Iberian Nanotechnology Laboratory (INL) , Av. Mestre José Veiga , 4715-330 Braga , Portugal
| | - Aron W Cummings
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and BIST , Campus UAB , 08193 Barcelona , Spain
| | - Roberto Robles
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and BIST , Campus UAB , 08193 Barcelona , Spain
| | - Pablo Ordejón
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and BIST , Campus UAB , 08193 Barcelona , Spain
| | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and BIST , Campus UAB , 08193 Barcelona , Spain
- ICREA - Institució Catalana de Recerca i Estudis Avançats , 08010 Barcelona , Spain
| |
Collapse
|
15
|
Berghäuser G, Bernal-Villamil I, Schmidt R, Schneider R, Niehues I, Erhart P, Michaelis de Vasconcellos S, Bratschitsch R, Knorr A, Malic E. Inverted valley polarization in optically excited transition metal dichalcogenides. Nat Commun 2018; 9:971. [PMID: 29511185 PMCID: PMC5840402 DOI: 10.1038/s41467-018-03354-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 02/07/2018] [Indexed: 11/16/2022] Open
Abstract
Large spin-orbit coupling in combination with circular dichroism allows access to spin-polarized and valley-polarized states in a controlled way in transition metal dichalcogenides. The promising application in spin-valleytronics devices requires a thorough understanding of intervalley coupling mechanisms, which determine the lifetime of spin and valley polarizations. Here we present a joint theory-experiment study shedding light on the Dexter-like intervalley coupling. We reveal that this mechanism couples A and B excitonic states in different valleys, giving rise to an efficient intervalley transfer of coherent exciton populations. We demonstrate that the valley polarization vanishes and is even inverted for A excitons, when the B exciton is resonantly excited and vice versa. Our theoretical findings are supported by energy-resolved and valley-resolved pump-probe experiments and also provide an explanation for the recently measured up-conversion in photoluminescence. The gained insights might help to develop strategies to overcome the intrinsic limit for spin and valley polarizations.
Collapse
Affiliation(s)
- Gunnar Berghäuser
- Department of Physics, Chalmers University of Technology, Gothenburg, 41296, Sweden.
| | - Ivan Bernal-Villamil
- Department of Physics, Chalmers University of Technology, Gothenburg, 41296, Sweden
| | - Robert Schmidt
- Institute of Physics and Center for Nanotechnology, University of Münster, Münster, 48149, Germany
| | - Robert Schneider
- Institute of Physics and Center for Nanotechnology, University of Münster, Münster, 48149, Germany
| | - Iris Niehues
- Institute of Physics and Center for Nanotechnology, University of Münster, Münster, 48149, Germany
| | - Paul Erhart
- Department of Physics, Chalmers University of Technology, Gothenburg, 41296, Sweden
| | | | - Rudolf Bratschitsch
- Institute of Physics and Center for Nanotechnology, University of Münster, Münster, 48149, Germany
| | - Andreas Knorr
- Institut für Theoretische Physik, Technische Universität Berlin, Berlin, 10623, Germany
| | - Ermin Malic
- Department of Physics, Chalmers University of Technology, Gothenburg, 41296, Sweden
| |
Collapse
|
16
|
Yang Z, Xu M, Cheng X, Tong H, Miao X. Manipulation of dangling bonds of interfacial states coupled in GeTe-rich GeTe/Sb 2Te 3 superlattices. Sci Rep 2017; 7:17353. [PMID: 29229978 PMCID: PMC5725461 DOI: 10.1038/s41598-017-17671-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/28/2017] [Indexed: 11/09/2022] Open
Abstract
Superlattices consisting of stacked nano-sized GeTe and Sb2Te3 blocks have attracted considerable attention owing to their potential for an efficient non-melting switching mechanism, associated with complex bonding between blocks. Here, we propose possible atomic models for the superlattices, characterized by different interfacial bonding types. Based on interplanar distances extracted from ab initio calculations and electron diffraction measurements, we reveal possible intercalation of dangling bonds as the GeTe content in the superlattice increases. The dangling bonds were further confirmed by X-ray photoelectron spectroscopy, anisotropic temperature dependent resistivity measurements down to 2 K and magnetotransport analysis. Changes of partially coherent decoupled topological surfaces states upon dangling bonds varying contributed to the switching mechanism. Furthermore, the topological surface states controlled by changing the bonding between stacking blocks may be optimized for multi-functional applications.
Collapse
Affiliation(s)
- Zhe Yang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Ming Xu
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xiaomin Cheng
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hao Tong
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China.
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Xiangshui Miao
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
- Wuhan National High Magnetic Field Centre, Huazhong University of Science and Technology, Wuhan, 430074, China
| |
Collapse
|
17
|
Zhang ZZ, Song XX, Luo G, Deng GW, Mosallanejad V, Taniguchi T, Watanabe K, Li HO, Cao G, Guo GC, Nori F, Guo GP. Electrotunable artificial molecules based on van der Waals heterostructures. SCIENCE ADVANCES 2017; 3:e1701699. [PMID: 29062893 PMCID: PMC5650488 DOI: 10.1126/sciadv.1701699] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/25/2017] [Indexed: 06/02/2023]
Abstract
Quantum confinement has made it possible to detect and manipulate single-electron charge and spin states. The recent focus on two-dimensional (2D) materials has attracted significant interests on possible applications to quantum devices, including detecting and manipulating either single-electron charging behavior or spin and valley degrees of freedom. However, the most popular model systems, consisting of tunable double-quantum-dot molecules, are still extremely difficult to realize in these materials. We show that an artificial molecule can be reversibly formed in atomically thin MoS2 sandwiched in hexagonal boron nitride, with each artificial atom controlled separately by electrostatic gating. The extracted values for coupling energies at different regimes indicate a single-electron transport behavior, with the coupling strength between the quantum dots tuned monotonically. Moreover, in the low-density regime, we observe a decrease of the conductance with magnetic field, suggesting the observation of Coulomb blockade weak anti-localization. Our experiments demonstrate for the first time the realization of an artificial quantum-dot molecule in a gated MoS2 van der Waals heterostructure, which could be used to investigate spin-valley physics. The compatibility with large-scale production, gate controllability, electron-hole bipolarity, and new quantum degrees of freedom in the family of 2D materials opens new possibilities for quantum electronics and its applications.
Collapse
Affiliation(s)
- Zhuo-Zhi Zhang
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiang-Xiang Song
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Gang Luo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guang-Wei Deng
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Vahid Mosallanejad
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Takashi Taniguchi
- National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan
| | - Hai-Ou Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Gang Cao
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guang-Can Guo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Franco Nori
- CEMS, RIKEN, Wako-shi, Saitama 351-0198, Japan
- Department of Physics, University of Michigan, Ann Arbor, MI 48109–1040, USA
| | - Guo-Ping Guo
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| |
Collapse
|
18
|
Ilić S, Meyer JS, Houzet M. Enhancement of the Upper Critical Field in Disordered Transition Metal Dichalcogenide Monolayers. PHYSICAL REVIEW LETTERS 2017; 119:117001. [PMID: 28949202 DOI: 10.1103/physrevlett.119.117001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Indexed: 06/07/2023]
Abstract
We calculate the effect of impurities on the superconducting phase diagram of transition metal dichalcogenide monolayers in the presence of an in-plane magnetic field. Because of strong intrinsic spin-orbit coupling, the upper critical field greatly surpasses the Pauli limit at low temperatures. We find that it is insensitive to intravalley scattering and, ultimately, limited by intervalley scattering.
Collapse
Affiliation(s)
- Stefan Ilić
- Univ. Grenoble Alpes, CEA, INAC-PHELIQS, F-38000 Grenoble, France
| | - Julia S Meyer
- Univ. Grenoble Alpes, CEA, INAC-PHELIQS, F-38000 Grenoble, France
| | - Manuel Houzet
- Univ. Grenoble Alpes, CEA, INAC-PHELIQS, F-38000 Grenoble, France
| |
Collapse
|
19
|
Spin-relaxation time in materials with broken inversion symmetry and large spin-orbit coupling. Sci Rep 2017; 7:9949. [PMID: 28855600 PMCID: PMC5577210 DOI: 10.1038/s41598-017-09759-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 07/31/2017] [Indexed: 11/08/2022] Open
Abstract
We study the spin-relaxation time in materials where a large spin-orbit coupling (SOC) is present which breaks the spatial inversion symmetry. Such a spin-orbit coupling is realized in zincblende structures and heterostructures with a transversal electric field and the spin relaxation is usually described by the so-called D'yakonov-Perel' (DP) mechanism. We combine a Monte Carlo method and diagrammatic calculation based approaches in our study; the former tracks the time evolution of electron spins in a quasiparticle dynamics simulation in the presence of the built-in spin-orbit magnetic fields and the latter builds on the spin-diffusion propagator by Burkov and Balents. Remarkably, we find a parameter free quantitative agreement between the two approaches and it also returns the conventional result of the DP mechanism in the appropriate limit. We discuss the full phase space of spin relaxation as a function of SOC strength, its distribution, and the magnitude of the momentum relaxation rate. This allows us to identify two novel spin-relaxation regimes; where spin relaxation is strongly non-exponential and the spin relaxation equals the momentum relaxation. A compelling analogy between the spin-relaxation theory and the NMR motional narrowing is highlighted.
Collapse
|
20
|
Garcia JH, Cummings AW, Roche S. Spin Hall Effect and Weak Antilocalization in Graphene/Transition Metal Dichalcogenide Heterostructures. NANO LETTERS 2017; 17:5078-5083. [PMID: 28715194 DOI: 10.1021/acs.nanolett.7b02364] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on a theoretical study of the spin Hall Effect (SHE) and weak antilocalization (WAL) in graphene/transition metal dichalcogenide (TMDC) heterostructures, computed through efficient real-space quantum transport methods, and using realistic tight-binding models parametrized from ab initio calculations. The graphene/WS2 system is found to maximize spin proximity effects compared to graphene on MoS2, WSe2, or MoSe2 with a crucial role played by disorder, given the disappearance of SHE signals in the presence of strong intervalley scattering. Notably, we found that stronger WAL effects are concomitant with weaker charge-to-spin conversion efficiency. For further experimental studies of graphene/TMDC heterostructures, our findings provide guidelines for reaching the upper limit of spin current formation and for fully harvesting the potential of two-dimensional materials for spintronic applications.
Collapse
Affiliation(s)
- Jose H Garcia
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology , Campus UAB, 08193 Barcelona, Spain
| | - Aron W Cummings
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology , Campus UAB, 08193 Barcelona, Spain
| | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology , Campus UAB, 08193 Barcelona, Spain
- ICREA - Institució Catalana de Recerca i Estudis Avançats , 08010 Barcelona, Spain
| |
Collapse
|
21
|
Jnawali G, Huang M, Hsu JF, Lee H, Lee JW, Irvin P, Eom CB, D'Urso B, Levy J. Room-Temperature Quantum Transport Signatures in Graphene/LaAlO 3 /SrTiO 3 Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1603488. [PMID: 28042885 DOI: 10.1002/adma.201603488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/23/2016] [Indexed: 06/06/2023]
Abstract
High mobility graphene field-effect devices, fabricated on the complex-oxide heterostructure LaAlO3 /SrTiO3 , exhibit quantum interference signatures up to room temperature. The oxide material is believed to play a critical role in suppressing short-range and phonon contributions to scattering. The ability to maintain pseudospin coherence at room temperature holds promise for the realization of new classical and quantum information technologies.
Collapse
Affiliation(s)
- Giriraj Jnawali
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA, 15260, USA
| | - Mengchen Huang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA, 15260, USA
| | - Jen-Feng Hsu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA, 15260, USA
| | - Hyungwoo Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jung-Woo Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Patrick Irvin
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA, 15260, USA
| | - Chang-Beom Eom
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Brian D'Urso
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA, 15260, USA
| | - Jeremy Levy
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, Pittsburgh, PA, 15260, USA
| |
Collapse
|
22
|
Ochoa H, Zarzuela R, Tserkovnyak Y. Emergent Gauge Fields from Curvature in Single Layers of Transition-Metal Dichalcogenides. PHYSICAL REVIEW LETTERS 2017; 118:026801. [PMID: 28128602 DOI: 10.1103/physrevlett.118.026801] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Indexed: 05/06/2023]
Abstract
We analyze the electron dynamics in corrugated layers of transition-metal dichalcogenides. Due to the strong spin-orbit coupling, the intrinsic (Gaussian) curvature leads to an emergent gauge field associated with the Berry connection of the spinor wave function. We discuss the gauge field created by topological defects of the lattice, namely, tetragonal and octogonal disclinations and edge dislocations. Ripples and topological disorder induce the same dephasing effects as a random magnetic field, suppressing the weak localization effects. This geometric magnetic field can be detected in an Aharonov-Bohm interferometry experiment by measuring the local density of states in the vicinity of corrugations.
Collapse
Affiliation(s)
- Héctor Ochoa
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Ricardo Zarzuela
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Yaroslav Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| |
Collapse
|