Degenerate excitons in strongly spin-orbit coupled heterolayers

ORAL

Abstract

We study the optical response and exciton properties of two-dimensional topological systems with strong spin-orbit coupling, using ab-initio GW and Bethe-Salpeter equation (BSE) calculations. We develop a new method to derive group representations of exciton states directly from ab initio calculations without any assumption on the character of the envelope functions. Our analyses show that, for appropriate systems, it is possible for the two lowest-energy optically active excitons from a single valley to be degenerate. By construction of a smooth gauge, the envelope functions of these degenerate excitons exhibit 1s-like characters. Our finding suggests these material systems are very promising for many applications in optoelectronics.

*This work was supported by the Theory of Materials Program at the Lawrence Berkeley National Laboratory funded by the U.S. Department of Energy, Office of Basic Energy Sciences under Contract No. DE-AC02-05CH11231, and by the National Science Foundation. Computational resources were provided by NERSC and XSEDE.

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Presenters

  • Jiawei Ruan

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory

Authors

  • Jiawei Ruan

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory

  • Zhenglu Li

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory; University of California at Berkeley
    • University of California at Berkeley and Lawrence Berkeley National Laboratory

  • Chin Shen Ong

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • University of California, Berkeley
    • Department of Physics and Astronomy, Uppsala University

  • Steven G Louie

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • University of California Berkeley
    • University of California, Berkeley
    • University of California at Berkeley; Lawrence Berkeley National Laboratory
    • University of California at Berkeley and Lawrence Berkeley National Laboratory
    • UC berkeley
    • University of California at Berkeley and Lawrence Berkeley National Lab
    • UC Berkeley & Lawrence Berkeley National Laboratory