Metallic Quantized Anomalous Hall Effect without Chiral Edge States

Fuente: arXiv
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Main Authors: Bai, Kai-Zhi, Fu, Bo, Zhang, Zhenyu, Shen, Shun-Qing
Format: Preprint
Published: 2023
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author Bai, Kai-Zhi
Fu, Bo
Zhang, Zhenyu
Shen, Shun-Qing
author_facet Bai, Kai-Zhi
Fu, Bo
Zhang, Zhenyu
Shen, Shun-Qing
contents The quantum anomalous Hall effect (QAHE) is a topological state of matter with a quantized Hall resistance. It has been observed in some two-dimensional insulating materials such as magnetic topological insulator films and twisted bilayer graphene. These materials are insulating in the bulk, but possess chiral edge states carrying the edge current around the systems. Here we discover a metallic QAHE in a topological insulator film with magnetic sandwich heterostructure, in which the Hall conductance is quantized to $e^{2}/h$, but the longitudinal conductance remains finite. This effect is attributed to the existence of a pair of massless Dirac cones of surface fermions, with each contributing half of the Hall conductance due to quantum anomaly. It is not characterized by a Chern number and not associated to any chiral edge states. Our study offers novel insights into topological transport phenomena and topological metallic states of matter.
format Preprint
id arxiv_https___arxiv_org_abs_2308_05963
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Metallic Quantized Anomalous Hall Effect without Chiral Edge States
Bai, Kai-Zhi
Fu, Bo
Zhang, Zhenyu
Shen, Shun-Qing
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
The quantum anomalous Hall effect (QAHE) is a topological state of matter with a quantized Hall resistance. It has been observed in some two-dimensional insulating materials such as magnetic topological insulator films and twisted bilayer graphene. These materials are insulating in the bulk, but possess chiral edge states carrying the edge current around the systems. Here we discover a metallic QAHE in a topological insulator film with magnetic sandwich heterostructure, in which the Hall conductance is quantized to $e^{2}/h$, but the longitudinal conductance remains finite. This effect is attributed to the existence of a pair of massless Dirac cones of surface fermions, with each contributing half of the Hall conductance due to quantum anomaly. It is not characterized by a Chern number and not associated to any chiral edge states. Our study offers novel insights into topological transport phenomena and topological metallic states of matter.
title Metallic Quantized Anomalous Hall Effect without Chiral Edge States
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2308.05963