Chern Number Engineering in a Layered Topological Magnet
Abstract
A central theme in condensed matter physics is to create and understand exotic states of matter by probing the interplay between symmetry and topology. One prime example is the Chern insulator, a quantum Hall insulator without Landau level formation. Despite the rapid progress of this field during the last few years, many outstanding challenges still remain in the creation and control of Chern insulators. These challenges include continuously tuning the topological phase transition, engineering interactions between topological states, switching on and off Chern insulator devices, and creating and controlling high-Chern number topological insulators. The roadblock to address these challenges is mainly due to the lack of suitable material platforms. Recently, MnBi2Te4 becomes the first material with intrinsic spin order to host Chern insulator states. The objective of this proposal is to develop controllable MBE growth of high-quality MnBi2Te4 films and heterostructures with Chern number engineering. We will experimentally explore the Chern insulator states and topological phase transitions in these samples. Our choice of MBE approaches, in complementary to popular mechanical exfoliation, lies in the potential precise control of defects, layer thickness, heterostructure with pristine interface, as well as its scalability towards DoD applications. Three main tasks include (1) Realization of magnetic field induced Chern insulator states; (2) Development and investigation of quantum anomalous Hall states with tunable Chern numbers; (3) Investigation of topological quantum phase transition of Chern insulator states. The success of our proposed program will not only pave the way towards realizing a variety of exotic states, but also opens new opportunities for topological quantum electronics and spintronics for transforming our defense technologies.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502110177
Entities
People
- Xiaodong Xu
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Washington