Biexcitons and exciton dynamics in low-dimensional systems from an <i>ab initio</i> interacting Green’s function formalism

ORAL

Abstract

The synthesis of quasi low-dimensional materials, such as the monolayer transition metal dichalcogenides (TMDs), opened the door to studying new classes of systems with nanoscale dimensionality confinement and weak electronic screening, leading to strongly enhanced electron interactions. Many of these systems host a variety of charged and neutral multiparticle excitations – such as excitons, trions, and biexcitons. We present here a first-principles formalism based on the interacting Green’s function to compute and understand these excitations and their dynamics. We apply our formalism and its associated code on high performing computers to the monolayer TMDs, predicting a diversity of multiparticle excitations with large binding energies (~20 meV) and complex valley and spin textures. We also show how this formalism can be employed to investigate other exciton-exciton interactions to understand challenging phenomena involving dynamics from first principles.

*This work was supported by the Center for Computational Study of Excited-State Phenomena in Energy Materials (C2SEPEM) at LBNL, funded by the U.S. DOE under Contract No. DE-AC02-05CH11231. Computational resources provided by NERSC and XSEDE.

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Presenters

  • Felipe Da Jornada

    • Materials Science and Engineering, Stanford University

Authors

  • Felipe Da Jornada

    • Materials Science and Engineering, Stanford University

  • Andrea Cepellotti

    • Harvard University
    • École Polytechnique Fédérale de Lausanne
    • School of Engineering and Applied Sciences, Harvard University
    • Materials Science & Mechanical Engineering, Harvard University

  • Steven Louie

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, C
    • University of California, Berkeley
    • Department of Physics, University of California, Berkeley
    • Lawrence Berkeley National Laboratory and University of California at Berkeley
    • Department of Physics, University of California at Berkeley and Lawrence Berkeley National Laboratory
    • Department of Physics, UC Berkeley
    • Physics, Unviersyt of Calfornia, Berkeley
    • Physics, University of California, Berkeley
    • Physics, University of California, Berkeley and Lawrence Berkeley National Lab