Defect Genome of 2d Topological Insulators for High Temperature Quantum Anomalous Hall Effect*

Currently experimental realization of the quantum anomalous Hall effect (QAHE) is limited at milli-Kelvin temperatures [1]. As a result, it is imperative that new materials be discovered that can host QAHE at higher operational temperatures. Stable defects (intrinsic/extrinsic) can be used to induce new topologies in synthesizable 2D materials [2, 3]. Starting with existing 2d databases [4,5], we designed a workflow to screen defects that are thermodynamically stable and induce non-trivial magnetic and topological properties in stable 2D topological materials. Our results show that cationic or anionic vacancies can potentially induce QAHE with a high Chern number. In addition, in systems where the d-band participates in the band inversion, we find the Chern number and the band gap to be sensitive to treatment of electronic correlations. We apply the linear-response method [6] to obtain the self-consistent Hubbard ‘U’ to predict the topology and gaps.
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[2] A. Pham et al, Phys. Rev. B 100, 241110(R) (2019).
[3] W. Ko et al, Phys. Rev. B 102, 115402 (2020).
[4] T. Olsen et al, Phys. Rev. Materials 3, 024005 (2019).
[5] A. Marrazzo et al, Nano Lett. 19, 8431 (2019).
[6] H. J. Kulik et al, Phys. Rev. Lett. 97, 103001 (2006).