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Sign-Free Determinant Quantum Monte Carlo Study of the Bilayer Hubbard and Two-Orbital Hubbard-Kanamori Models

ORAL

Abstract

Two-band Hubbard models, as prototypes for various strongly correlated systems, have attracted intense research interest over the past few decades. Determinant Quantum Monte Carlo (DQMC), an unbiased finite-temperature numerical technique well suited to study such models, generically suffers from the fermion sign problem. However, for some variations, e.g. the bilayer Hubbard model with symmetric electron-hole doping and the half-filled two-orbital Hubbard-Kanamori model, particle-hole symmetry can be utilized to perform sign-problem-free studies. Here, using DQMC we show that the bilayer Hubbard model possesses a Berezinskii–Kosterlitz–Thouless (BKT) transition to an inter-layer biexciton condensate at intermediate coupling and finite electron-hole doping. For the Hubbard-Kanamori model, we treat the full rotationally invariant interaction, including the Hubbard and Hund’s coupling terms, using a decoupling scheme which involves a 12-state auxiliary field per site, and present the magnetic correlation and phase transition results obtained from DQMC.

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Presenters

  • Xuxin Huang

    Applied Physics, Stanford University, Stanford University

Authors

  • Xuxin Huang

    Applied Physics, Stanford University, Stanford University

  • Martin Claassen

    Center for Computational Quantum Physics, The Flatiron Institute, Center for Computational Quantum Physics, Flatiron Institute

  • Brian Moritz

    SLAC National Accelerator Laboratory and Stanford University, SSRL Materials Science Division, SLAC National Accelerator Laboratory, SLAC, Stanford University, SIMES, SLAC, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA

  • Thomas Devereaux

    Stanford Univ, Materials Science and Engineering, Stanford University, Stanford University, SLAC National Accelerator Laboratory, Photon Sciences, Stanford Linear Accelerator (SLAC), SIMES, SLAC, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA, SLAC National Accelerator Lab.