Towards a topological phase diagram for SmB<sub>6</sub> alloys

ORAL

Abstract

SmB6 is a strongly correlated material that has been attributed as a topological insulator and a Kondo insulator. The bulk insulating character of SmB6 is surprisingly robust against nominal carrier doping, however the robustness of the band topology picture within alloys is less clear. I will present angle resolved photoemission measurements that characterize the loss of topological band structure features as a function of carrier doping and decoherence in Eu- and Ce- alloyed samples. Topologically associated features are observed out to unprecedented 30% Eu and 50% Ce concentrations. These properties are interpreted in the context of a recent re-designation of the conduction band, and provide the bases to propose a new low energy heirarchy of electronic symmetries involved in the insulating gap and topological surface states.

*This research used resources of the Advanced Light Source, a U.S. DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231. Operation of the ESM beam line at the National Synchrotron Light Source is supported by DOE Office of Science User Facility Program operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DEAC02-98CH10886. ARPES measurements at New York University were supported by the National Science Foundation under Grant No. DMR-2105081. M. S. S., B. Y. K., J. W. L., and B. K. C. were supported by National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT and Future Planning (No. NRF2017R1A2B2008538). L. M. is supported by the National Natural Science Foundation of China (Grants No. U2032156 and No. 12004071) and Natural Science Foundation of Jiangsu Province, China (Grant No. BK20200348).

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Publication: 1. Mapping out the emergence of topological features in the highly alloyed topological Kondo insulators Sm1-xMxB6 (M=Eu, Ce), Yishuai Xu, Erica C. Kotta, M. S. Song, B. Y. Kang, J. W. Lee, B. K. Cho, Shouzheng Liu, Turgut Yilmaz, Elio Vescovo, Jonathan D. Denlinger, Lin Miao, and L. Andrew Wray, Physical Review B 104, 115118 (2021).

2. Robust coherence phenomena and surface states in magnetically alloyed SmB6, Lin Miao, Chul-Hee Min, Yishuai Xu, Erica C. Kotta, Rourav Basak, M. S. Song, B. Y. Kang, B. K. Cho, K. Kißner, F. Reinert, Turgut Yilmaz, Elio Vescovo, Yi-De Chuang, Jonathan D. Denlinger, and L. Andrew Wray, Physical Review Letters 126, 136401 (2021).

Presenters

  • L. Andrew A Wray

    • New York University (NYU)
    • New York University

Authors

  • L. Andrew A Wray

    • New York University (NYU)
    • New York University

  • Yishuai Xu

    • New York Univ NYU

  • Erica Kotta

    • New York University (NYU)

  • Jae Woong Lee

    • Gwangju Institute of Science and Technology

  • Beongki Cho

    • School of Materials Science and Engineering, Gwangju Feedback and Support Institute of Science and Technology, Gwangju, 61005, South Korea
    • School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, South Korea
    • Gwangju Institute of Science and Technology

  • Shouzheng Liu

    • New York University

  • Turgut Yilmaz

    • Brookhaven National Laboratory

  • Elio Vescovo

    • Brookhaven National Laboratory
    • Brookhaven National Lab
    • Brookhaven National Laboratory, New York, USA

  • Jonathan D Denlinger

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab

  • Lin Miao

    • Southeast University
    • New York Univ NYU