Approaching quantum anomalous Hall effect in proximity-coupled YIG/graphene/h-BN sandwich structure
- Univ. of California, Riverside, CA (United States). Dept. of Physics and Astronomy
- National Inst. for Materials Science (NIMS), Tsukuba (Japan). Advanced Materials Lab.
- Univ. of California, Riverside, CA (United States). Dept. of Physics and Astronomy; The Ohio State Univ., Columbus, OH (United States). Dept. of Physics
Quantum anomalous Hall state is expected to emerge in Dirac electron systems such as graphene under both sufficiently strong exchange and spin-orbit interactions. In pristine graphene, neither interaction exists; however, both interactions can be acquired by coupling graphene to a magnetic insulator as revealed by the anomalous Hall effect. Here, we show enhanced magnetic proximity coupling by sandwiching graphene between a ferrimagnetic insulator yttrium iron garnet (YIG) and hexagonal-boron nitride (h-BN) which also serves as a top gate dielectric. By sweeping the top-gate voltage, we observe Fermi level-dependent anomalous Hall conductance. As the Dirac point is approached from both electron and hole sides, the anomalous Hall conductance reaches ¼ of the quantum anomalous Hall conductance 2e2/h. The exchange coupling strength is determined to be as high as 27 meV from the transition temperature of the induced magnetic phase. YIG/graphene/h-BN is an excellent heterostructure for demonstrating proximity-induced interactions in two-dimensional electron systems.
- Research Organization:
- Univ. of California, Riverside, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
- Grant/Contract Number:
- FG02-07ER46351; SC0010597; 1202559; 1610447
- OSTI ID:
- 1501548
- Alternate ID(s):
- OSTI ID: 1406647
- Journal Information:
- APL Materials, Vol. 6, Issue 2; ISSN 2166-532X
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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