Electronic Ground State in Bilayer Graphene with Realistic Coulomb Interactions

ORAL

Abstract

In bilayer graphene at charge neutrality, previous theoretical studies have shown that even with infinitesimal long-range electron-electron interactions, the quadratic band structure is susceptible to several different symmetry breaking ground states. This is in stark contrast to a recent numerical quantum Monte Carlo study [Pujari et. al., PRL 117, 086404 (2016)] showing that the short-range Hubbard interaction spontaneously generates a linear band that stabilises the metallic phase over a finite range of weak interactions. In this theoretical work, using a combination of renormalization group, quantum Monte Carlo and lattice perturbation theory, we address the question of what happens for a realistic model of the Coulomb interaction that includes both short-range and long-range components. Surprisingly, we find that the metallic phase remains stable without the generation of linear bands. We discuss the implications of this finding on the interpretation of available experiments.

*This work was supported by the Singapore National Research Foundation (NRF-NRFF2012-01) and Yale-NUS College.

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Presenters

  • Jia Ning Leaw

    • Centre for Advanced 2D Materials, National University of Singapore
    • National University of Singapore

Authors

  • Jia Ning Leaw

    • Centre for Advanced 2D Materials, National University of Singapore
    • National University of Singapore

  • Ho Kin Tang

    • Centre for Advanced 2D Materials, National University of Singapore
    • National University of Singapore

  • Igor Herbut

    • Simon Fraser Univ
    • Department of Physics, Simon Fraser University
    • Simon Fraser University

  • Pinaki Sengupta

    • School of Physical and Mathematical Sciences, Nanyang Technological University
    • Nanyang Technological University

  • Fakher Assaad

    • University of Wurzburg
    • Institut für Theoretische Physik und Astrophysik, Universität Würzburg
    • University Wuerzburg
    • Universität Würzburg
    • Physics, Universität Würzburg
    • University of Würzburg

  • Shaffique Adam

    • Centre for Advanced 2D Materials, National University of Singapore
    • Yale-NUS College
    • Department of Physics and Centre for Advanced 2D Materials, National University of Singapore
    • Yale-NUS College and Natl Univ of Singapore