Quantum anomalous Hall effect in graphene proximity coupled to an antiferromagnetic insulator

Zhenhua Qiao; Wei Ren; Hua Chen; L Bellaiche; Zhenyu Zhang; A H Macdonald; Qian Niu

doi:10.1103/PhysRevLett.112.116404

Quantum anomalous Hall effect in graphene proximity coupled to an antiferromagnetic insulator

Phys Rev Lett. 2014 Mar 21;112(11):116404. doi: 10.1103/PhysRevLett.112.116404. Epub 2014 Mar 18.

Authors

Zhenhua Qiao¹, Wei Ren², Hua Chen³, L Bellaiche⁴, Zhenyu Zhang⁵, A H Macdonald³, Qian Niu⁶

Affiliations

¹ Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China and ICQD, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China and Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA.
² Department of Physics, Shanghai University, Shanghai 200444, China and Department of Physics, The University of Arkansas, Fayetteville, Arkansas 72701, USA.
³ Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA.
⁴ Department of Physics, The University of Arkansas, Fayetteville, Arkansas 72701, USA.
⁵ ICQD, Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
⁶ Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA and International Center for Quantum Materials, Peking University, Beijing 100871, China.

PMID: 24702394
DOI: 10.1103/PhysRevLett.112.116404

Abstract

We propose realizing the quantum anomalous Hall effect by proximity coupling graphene to an antiferromagnetic insulator that provides both broken time-reversal symmetry and spin-orbit coupling. We illustrate our idea by performing ab initio calculations for graphene adsorbed on the (111) surface of BiFeO3. In this case, we find that the proximity-induced exchange field in graphene is about 70 meV, and that a topologically nontrivial band gap is opened by Rashba spin-orbit coupling. The size of the gap depends on the separation between the graphene and the thin film substrate, which can be tuned experimentally by applying external pressure.