A large-gap quantum spin Hall state in exfoliated Na3Bi-like two-dimensional materials

Jiang, Jingwen1; Guo, Xiaoqiu1; Ma, Zhuang1; Wang, Gui1; Xu, Yiguo2; Zhang, Xiuwen1,3

2022-07-01

10.1039/d2tc01755e

Journal of Materials Chemistry C   Impact Factor & Quartile

2050-7526

2050-7534

Two-dimensional (2D) topological insulators (TIs) with gapped 2D electronic structures and metallic edge states protected by time-reversal symmetry possess the intriguing quantum spin Hall effect that has attracted intensive attention recently. A large-gap quantum spin Hall state has been sought for decades, which is essential for realizing high-temperature topological devices based on 2D TIs. Here, we designed a class of large-gap 2D TIs by exfoliating Na3Bi-like alkali bismide three-dimensional Dirac semimetals, followed by modulation via external strain and an external electric field, predicting a quantum spin Hall state with a large gap of up to 0.473 eV. The designed 2D TIs (K2NaBi and Rb2NaBi monolayers) with benign dynamical, thermal, and mechanical stability have calculated exfoliation energies of 0.35-0.59 J m(-2) from density functional theory, which is much lower than the corresponding Na3Bi monolayer TI (0.81 J m(-2)) that is found to be dynamically unstable. The near band edge spin splitting magnitude of the designed 2D TIs increases significantly under an external electric field, with the corresponding spin texture changing from the non-helical Dresselhaus spin texture to the partially helical Rashba-Dresselhaus-like spin texture. Our work proposes a new arena to search for 2D topological insulators with large-gap quantum spin Hall states, which can be used for future spintronic devices and quantum computing.

SCI ; EI

English

Others

National Key R&D Program of China[2019YFB2204500] ; National Natural Science Foundation of China["61827815","11774239","11804230","12004256"] ; Shenzhen Science and Technology Innovation Commission["KQTD20180412181422399","KQTD20170810105439418","JCYJ20180507181858539","ZDSYS201707271554071"] ; High-Level University Construction Funds of SZU["860-000002081209","860000002110711"]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied

WOS:000829458400001

ROYAL SOC CHEMISTRY

20223212539972

Bismuth alloys ; Computation theory ; Electric fields ; Electronic structure ; Mechanical stability ; Monolayers ; Quantum computers ; Quantum theory ; Sodium alloys ; Spin Hall effect ; Textures ; Topological insulators

Alkali Metals:549.1 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Electricity: Basic Concepts and Phenomena:701.1 ; Magnetism: Basic Concepts and Phenomena:701.2 ; Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory:721.1 ; Computer Systems and Equipment:722 ; Probability Theory:922.1 ; Atomic and Molecular Physics:931.3 ; Quantum Theory; Quantum Mechanics:931.4

Web of Science

1.Shenzhen Univ, Coll Phys & Optoelect Engn, Shenzhen Key Lab Flexible Memory Mat & Devices, Shenzhen 518060, Peoples R China
2.Southern Univ Sci & Technol, Acad Adv Interdisciplinary Studies, Shenzhen 518055, Peoples R China
3.Univ Colorado, Renewable & Sustainable Energy Inst, Boulder, CO 80309 USA

Jiang, Jingwen,Guo, Xiaoqiu,Ma, Zhuang,et al. A large-gap quantum spin Hall state in exfoliated Na3Bi-like two-dimensional materials[J]. Journal of Materials Chemistry C,2022,10:11329-11337.

Jiang, Jingwen,Guo, Xiaoqiu,Ma, Zhuang,Wang, Gui,Xu, Yiguo,&Zhang, Xiuwen.(2022).A large-gap quantum spin Hall state in exfoliated Na3Bi-like two-dimensional materials.Journal of Materials Chemistry C,10,11329-11337.

Jiang, Jingwen,et al."A large-gap quantum spin Hall state in exfoliated Na3Bi-like two-dimensional materials".Journal of Materials Chemistry C 10(2022):11329-11337.