Time: 09:30 am (UTC/GMT+08:00, Beijing/Shanghai), Jun. 23 (Tue.), 2020

Online Meeting Room (zoom.com):  Click here to join the meeting

Meeting ID: 962 0368 5028

Speaker: XU Yong (Tsinghua/RIKEN)

Abstract:

Intrinsic magnetic topological insulators are novel states of quantum matter possessing both inherent magnetic order and topological electronic states, which offer a fertile playground to explore emergent quantum physics. The antiferromagnetic topological insulator MnBi2Te4 [1-4] is a rapidly rising star in the research field. The material is theoretically predicted to host rich topological quantum states (e.g., topological axion states, magnetic Weyl semimetal, and quantum anomalous Hall (QAH) effect). Exciting research progresses of the field will be introduced, including the findings of antiferromagnetic topological insulator states, intrinsic QAH effect, robust axion insulator and Chern insulator phases, high-Chern-number and high-temperature QAH effect, helical Chern insulator phase [1,4-8], etc. An outlook for future work will be given. To move forward, we proposed new candidate material systems with superior proprieties [9,10], including ferromagnetic topological insulators/semimetals in van der Waals heterostructures, large-gap QAH insulators with room-temperature ferromagnetism in lithium-decorated iron-based superconductor materials LiFeX (X=S, Se, Te), which are awaiting for experimental proof.

Reference:

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[2] J. Li, et al. Sci. Adv. 5, eaaw5685 (2019).

[3] D. Zhang, et al. Phys. Rev. Lett. 122, 206401 (2019).

[4] M. M. Otrokov, et al. Nature 576, 416 (2019).

[5] Y. Deng, et al. Science 367, 895 (2020).

[6] C. Liu, et al. Nature Mater. 19, 522 (2020).

[7] J. Ge, et al. Natl. Sci. Rev. nwaa089 (2020).

[8] C. Liu, et al. arXiv: 2001.08401.

[9] Z. Li, et al. arXiv: 2003.13485.

[10] Y. Li, et al. arXiv:1912.07461.