Diffusion quantum Monte Carlo study of excitonic complexes layered transition-metal dichalcogenides

POSTER

Abstract

The nonhydrogenic nature of the excitonic energy spectrum is due to lateral polarization effects in layered material (LM) crystals, which modify the form of the Coulomb interaction between charge carriers. We use quantum Monte Carlo (QMC) methods implemented in CASINO code [1] to extend Mott-Wannier models to provide numerically exact binding-energy (BE) data for all nonlocal screening strengths, including an analysis of limiting behavior. We classify the types of trions and biexcitons that can be observed in different transition-metal dichalcogenides (TMDs). We also investigate donor- and acceptor-bound charge-carrier complexes in TMDs, such as quintons and donor-bound biexcitons. These have similar binding energies to the experimentally measured biexciton BE, suggesting that larger charge-carrier complexes could be responsible for the observed peak ascribed to biexcitons [2].
[1] R.J. Needs et al., J. Phys.: Condens. Matter, 22, 023201 (2010).
[2] E. Mostaani, M. Szyniszewski, C. H. Price, R. Maezono, M. Danovich, R. J. Hunt, N. D. Drummon, V. I. Fal’ko, Phys.Rev.B 96, 075431 (2017).

*We acknowledge European Research Council synergy grant Hetero2D, the United Kingdom’s Engineering and Physical Sciences Research Council (EPSRC), and the European Graphene Flagship project.

Presenters

  • Elaheh Mostaani

    • Cambridge Graphene Centre, Electrical Engineering, University of Cambridge
    • Cambridge Graphene Centre, Electrical Engineering, University of cambridge

Authors

  • Elaheh Mostaani

    • Cambridge Graphene Centre, Electrical Engineering, University of Cambridge
    • Cambridge Graphene Centre, Electrical Engineering, University of cambridge

  • Marcin Szyniszewski

    • Department of Physics, Lancaster University

  • Cameron Price

    • Department of Physics, Lancaster University

  • Ryo Maezono

    • Japan Adv Inst of Sci and Tech
    • Japan Advanced Institute of Science and Technology, School of Information Science
    • Energy and Environment, Japan Adv Inst of Sci and Tech

  • Mark Danovich

    • National Graphene Institute, University of Manchester

  • Ryan Hunt

    • Department of Physics, Lancaster University

  • Neil Drummond

    • Department of Physics, Lancaster University

  • Andrea Ferrari

    • Univ of Cambridge
    • Cambridge Graphene Centre, Electrical Engineering, University of Cambridge
    • Cambridge Graphene Centre, University of Cambridge
    • Cambridge Graphene Centre, Electrical Engineering, University of cambridge

  • Vladimir Falko

    • National Graphene Institute, University of Manchester