Electrical Manipulation of Topological Phases in a Quantum Anomalous Hall Insulator

Su Kong Chong, Peng Zhang, Jie Li, Yinong Zhou, Jingyuan Wang, Huairuo Zhang, Albert V. Davydov, Christopher Eckberg, Peng Deng, Lixuan Tai, Jing Xia, Ruqian Wu, Kang L. Wang

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Quantum anomalous Hall phases arising from the inverted band topology in magnetically doped topological insulators have emerged as an important subject of research for quantization at zero magnetic fields. Though necessary for practical implementation, sophisticated electrical control of molecular beam epitaxy (MBE)-grown quantum anomalous Hall matter have been stymied by growth and fabrication challenges. Here, a novel procedure is demonstrated, employing a combination of thin-film deposition and 2D material stacking techniques, to create dual-gated devices of the MBE-grown quantum anomalous Hall insulator, Cr-doped (Bi,Sb)2Te3. In these devices, orthogonal control over the field-induced charge density and the electric displacement field is demonstrated. A thorough examination of material responses to tuning along each control axis is presented, realizing magnetic property control along the former and a novel capability to manipulate the surface exchange gap along the latter. Through electrically addressing the exchange gap, the capabilities to either strengthen the quantum anomalous Hall state or suppress it entirely and drive a topological phase transition to a trivial state are demonstrated. The experimental result is explained using first principle theoretical calculations, and establishes a practical route for in situ control of quantum anomalous Hall states and topology.

Original languageEnglish
Article number2207622
JournalAdvanced Materials
Volume35
Issue number11
DOIs
Publication statusPublished - 2023 Mar 16

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering

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