Light-Tunable Surface State and Hybridization Gap in Magnetic Topological Insulator MnBi8Te13

Haoyuan Zhong; Changhua Bao; Huan Wang; Jiaheng Li; Zichen Yin; Yong Xu; Wenhui Duan; Tian-Long Xia; Shuyun Zhou

doi:10.1021/acs.nanolett.1c01448

Light-Tunable Surface State and Hybridization Gap in Magnetic Topological Insulator MnBi₈Te₁₃

Nano Lett. 2021 Jul 28;21(14):6080-6086. doi: 10.1021/acs.nanolett.1c01448. Epub 2021 Jul 9.

Authors

Haoyuan Zhong¹, Changhua Bao¹, Huan Wang², Jiaheng Li¹, Zichen Yin¹, Yong Xu^{1

3}, Wenhui Duan^{1

3}, Tian-Long Xia², Shuyun Zhou^{1

3}

Affiliations

¹ State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P. R. China.
² Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, P. R. China.
³ Frontier Science Center for Quantum Information, Beijing 100084, P. R. China.

PMID: 34242038
DOI: 10.1021/acs.nanolett.1c01448

Abstract

MnBi₈Te₁₃ is an intrinsic ferromagnetic (FM) topological insulator with different complex surface terminations. Resolving the electronic structures of different termination surfaces and manipulation of the electronic state are important. Here, by using micrometer spot time- and angle-resolved photoemission spectroscopy (μ-TrARPES), we resolve the electronic structures and reveal the ultrafast dynamics upon photoexcitation. Photoinduced filling of the surface state hybridization gap is observed for the Bi₂Te₃ quintuple layer directly above MnBi₂Te₄ accompanied by a nontrivial shift of the surface state, suggesting light-tunable interlayer interaction. Relaxation of photoexcited electrons and holes is observed within 1-2 ps. Our work reveals photoexcitation as a potential control knob for tailoring the interlayer interaction and surface state of MnBi₈Te₁₃.

Keywords: hybridization gap; light-tunable interlayer interaction; magnetic topological insulator, MnBi8Te13; μ-TrARPES.