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.

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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