Exploring Next Generation Quantum Anomalous Hall Insulators in Epitaxial Topological Magnet Films and Heterostructures
Abstract
The quantum anomalous Hall (QAH) state is a topological quantum state with quantized Hall resistance and zero longitudinal resistance in the absence of external magnetic fields. The dissipationless chiral current that flows along the edges of the QAH sample, known as chiral edge current, opens the door to electronics, spintronics and topological quantum computations with low-energy dissipation. However, the QAH effect in magnetically doped topological insulator systems relies on the introduction of magnetic dopants which inevitably degrade sample quality by introducing disorders and thus can only appear at the temperature below 2 K. This low working temperature is the main obstacle for exploring new physics and accessing potential applications of the QAH phenomenon. Alternative QAH platforms are required to overcome the above fundamental material limitations and realize practical quantum technologies. This project aims to experimentally explore a new generation of QAH/Chern insulators in molecular beam epitaxy grown intrinsic magnetic topological insulator, MnBi2Te4 thin films/heterostructures. Because the magnetic exchange gap of MnBi2Te4 is orders of magnitude larger than that in magnetically doped QAH sample, the QAH/Chern insulators are expected to have a significantly enhanced working temperature. Based on the high temperature QAH/Chern insulators, we will investigate the fundamental properties of the QAH/Chern insulators, including scaling behaviors of the plateau to plateau transition and current-induced breakdown, and probe the spin polarization of the QAH chiral edge current. The success of our proposed program will provide a new approach for achieving the high temperature QAH insulators, clarify the different microscopic physics between the QAH and the well-studied quantum Hall effect. Our studies will carry far-reaching scientific and technological impact for the development of quantum information science.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 11, 2022
- Source ID
- W911NF2210159
Entities
People
- Cui-Zu Chang
Organizations
- Army Contracting Command
- Pennsylvania State University
- United States Army