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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.

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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