Antiferromagnetic Order and Non-Equilibrium Distributions in the Floquet-Engineered Hubbard Model

ORAL

Abstract

The periodically driven half-filled two-dimensional Hubbard model is studied via a saddle point plus fluctuations analysis of the Keldysh action. The drive is implemented as an alternating electric field, and the system is coupled to a metallic substrate in thermal equilibrium to allow for a non-equilibrium steady state synchronized to the drive. For drive frequencies below the equilibrium gap, and strong enough drive amplitudes, the mean-field equation has multiple solutions with a substantial time-dependent component. Even for "Magnus" drive frequencies much larger than the equilibrium gap, a one-loop analysis around the mean-field solution shows that even if no real electron-hole pairs are excited, the ac drive produces a highly excited, generically non-thermal distribution of fluctuations, which can affect the physics significantly, for example destroying zero-temperature long-ranged antiferromagnetic order for large enough drive amplitudes.

*This research was funded by the Danish National Research Foundation (CNG and QDev), the Basic Energy Sciences Division of the U.S. Department of Energy (DE-SC0018218) and the Deutsche Forschungsgemeinschaft through the Emmy Noether program (KA 3360/2-1).

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Presenters

  • Jens Paaske

    • Niels Bohr Institute, University of Copenhagen

Authors

  • Nicklas Walldorf

    • Department of Micro- and Nanotechnology, Technical University of Denmark

  • Dante Kennes

    • Freie Universitaet Berlin
    • Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universitat Berlin
    • Max Planck Institute for the Structure and Dynamics of Matter
    • Freie Universität Berlin
    • Physics, Freie Universität Berlin
    • Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin
    • Fachbereich Physik, Freie Universit{\"a}t Berlin
    • Columbia University

  • Jens Paaske

    • Niels Bohr Institute, University of Copenhagen

  • Andrew Millis

    • Center for Computational Quantum Physics, Flatiron Institute
    • Physics, Columbia University
    • Columbia University
    • Department of Physics, Columbia University
    • Center for Computational Quantum Physics, Flatiron Institute, NY, NY, 10010
    • National Institute of Materials Science
    • Center for Computational Quantum Physics, Flatiorn Institute, Physics Department, Columbia University