Tunable unconventional integer quantum Hall effect in two-dimensional Dirac-Weyl systems

Jin, Y. J.1,2,3; Xu, Y.2,3,4; Xiao, X. L.5; Chen, Z. J.6; Xu, H.1,2,3,7

2024-02-22

10.1103/PhysRevB.109.L081404

PHYSICAL REVIEW B   影响因子和分区

2469-9950

2469-9969

Two-dimensional (2D) Dirac semimetals possess intriguing properties due to their low-energy excitations behaving like Dirac fermions. A hallmark of these materials is the unconventional integer quantum Hall effect (IQHE), originating from the quantized Berry phase of Dirac fermions. Herein, using symmetry analysis, tightbinding models, and numerical calculations, we reveal 2D Dirac-Weyl fermions in inversion symmetry breaking systems that exhibit tunable unconventional IQHE. These unique 2D fermions are characterized by a pair of helical edge states related by time-reversal symmetry T, which connect the projections of a Dirac point and two separate Weyl nodes, indicating that the Dirac and Weyl points are interconnected as a whole. We show that these 2D Dirac-Weyl fermions exhibit a tunable unconventional IQHE, featuring a Hall plateau sequence shifted by three units of 2e2 h . The distance between adjacent quantized Hall plateaus can be adjusted by strain, which is a unique feature that distinguishes from what is observed in graphene. Through first-principles calculations, we identify an ideal candidate material for hosting 2D Dirac-Weyl fermions, offering a promising avenue for experimental verification. Our findings open up a door to exploring unconventional IQHE in condensed-matter systems beyond graphene.

SCI ; EI

英语

通讯

National Key R&D Program of China[2022YFA1403700] ; Shenzhen Science and Technol-ogy Program[RCYX20200714114523069] ; National Natural Science Foundation of China[12374182] ; Scientific Research Starting Foundation of Ningbo University of Technology[2022KQ51] ; China Postdoctoral Science Foundation[2023M743783]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:001199479500004

AMER PHYSICAL SOC

PHYSICS

Web of Science

1.South China Normal Univ, Guangdong Basic Res Ctr Excellence Struct & Fundam, Sch Phys, Guangdong Prov Key Lab Quantum Engn & Quantum Mat, Guangzhou 510006, Peoples R China
2.Southern Univ Sci & Technol, Dept Phys, Shenzhen 518055, Peoples R China
3.Southern Univ Sci & Technol, Inst Quantum Sci & Engn, Shenzhen 518055, Peoples R China
4.Ningbo Univ Technol, Inst Micro Nano Mat & Devices, Ningbo 315016, Zhejiang, Peoples R China
5.Chongqing Univ, Dept Phys, Chongqing 400044, Peoples R China
6.Songshan Lake Mat Lab, Dongguan 523808, Peoples R China
7.Quantum Sci Ctr Guangdong Hong Kong Macao Greater, Hong Kong 518045, Peoples R China

Jin, Y. J.,Xu, Y.,Xiao, X. L.,et al. Tunable unconventional integer quantum Hall effect in two-dimensional Dirac-Weyl systems[J]. PHYSICAL REVIEW B,2024,109(8).

Jin, Y. J.,Xu, Y.,Xiao, X. L.,Chen, Z. J.,&Xu, H..(2024).Tunable unconventional integer quantum Hall effect in two-dimensional Dirac-Weyl systems.PHYSICAL REVIEW B,109(8).

Jin, Y. J.,et al."Tunable unconventional integer quantum Hall effect in two-dimensional Dirac-Weyl systems".PHYSICAL REVIEW B 109.8(2024).