首页|On the half-quantized Hall conductance of massive surface electrons in magnetic topological insulator films

On the half-quantized Hall conductance of massive surface electrons in magnetic topological insulator films

扫码查看
原文链接
  • 万方数据
  • 维普
In topological insulators,massive surface states resulting from local symmetry breaking were thought to exhibit a half-quantized Hall conductance,obtained from the low-energy effective model in an infinite Brillouin zone.In a lattice model,the surface band is composed of a combination of surface states and bulk states.The massive surface states alone may not be enough to support an exact one-half quantized surface Hall conductance in a finite Brillouin zone and the whole surface band always gives an integer quantized Hall conductance as enforced by the TKNN theorem.To explore this,we investigate the band structures of a lattice model describing the magnetic topological insulator film that supports the axion insulator,Chern insulator,and semi-magnetic topological insulator phases.We reveal that the gapped and gapless surface bands in the three phases are characterized by an integer-quantized Hall conductance and a half-quantized Hall conductance,respectively.We propose an effective model to de-scribe the three phases and show that the low-energy dispersion of the surface bands inherits from the surface Dirac fermions.The gapped surface band manifests a nearly half-quantized Hall conductance at low energy near the center of Brillouin zone,but is compensated by another nearly half-quantized Hall conductance at high energy near the boundary of Brillouin zone because a single band can only have an integer-quantized Hall conductance.The gapless band hosts a zero Hall conductance at low energy but is compensated by another half-quantized Hall conductance at high energy,and thus the half-quantized Hall conductance can only originate from the gapless band.Moreover,we calculate the layer-resolved Hall conductance of the system.The conclusion suggests that the individual gapped surface band alone does not support the half-quantized surface Hall effect in a lattice model.

magnetic topological insulatorDirac equationhalf-quantized Hall conductance

Rui Chen、Shun-Qing Shen

展开 >

Department of Physics,The University of Hong Kong,Hong Kong 999077,China

Department of Physics,Hubei University,Wuhan 430062,China

Research Grants Council,University Grants Committee,Hong KongResearch Grants Council,University Grants Committee,Hong KongNational Key R&D Program of ChinaNational Natural Science Foundation of ChinaChutian Scholars Program in Hubei Province

C7012-21G173012202019YFA030860312304195

2024

10.1007/s11433-023-2352-0

中国科学:物理学 力学 天文学(英文版)
中国科学院

中国科学:物理学 力学 天文学(英文版)

CSTPCD
影响因子：0.91
ISSN：1674-7348
年,卷(期)：2024.67(6)