Quantum Theory of Exciton Magnetic Moment in 2D Semiconductors

ORAL

Abstract

We present a quantum mechanical derivation of the exciton orbital magnetic moment in two-dimensional (2D) semiconductors using many-body first-order perturbation theory. Our analysis reveals an additional non-trivial contribution to the exciton magnetic moment —an effect that extends beyond the conventional treatment of electron-hole interaction in an average sense typically considered in the literature. Using this framework, we compute the effective g-factor of excitons in materials exhibiting three-fold rotational symmetry and broken inversion symmetry, such as the 2D transition metal dichalcogenides (TMDs), and biased bilayer graphene. These systems possess a valley degree of freedom that couples with an external magnetic field, leading to valley-splitting of exciton levels and providing an experimental probe of the effective g factor.

*This work is supported by the U.S. Department of Energy and computational resources from NERSC and TACC Frontera.

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Presenters

  • Gurjyot Sethi

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

Authors

  • Gurjyot Sethi

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

  • Fang Zhang

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

  • Jiawei Ruan

    • UC Berkeley
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory

  • Steven G Louie

    • University of California, Berkeley
    • University of California, Berkeley and Lawrence Berkeley National Lab
    • University of California, Berkeley and Lawrence Berkeley National Laboratory
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Department of Physics, University of California at Berkeley, Berkeley, CA, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA