Quantum Floquet engineering with an exactly solvable tight-binding chain in a cavity

Communications Physics, vol. 5

Abstract

Abstract Recent experimental advances enable the manipulation of quantum matter by exploiting the quantum nature of light. However, paradigmatic exactly solvable models, such as the Dicke, Rabi or Jaynes-Cummings models for quantum-optical systems, are scarce in the corresponding solid-state, quantum materials context. Focusing on the long-wavelength limit for the light, here, we provide such an exactly solvable model given by a tight-binding chain coupled to a single cavity mode via a quantized version of the Peierls substitution. We show that perturbative expansions in the light-matter coupling have to be taken with care and can easily lead to a false superradiant phase. Furthermore, we provide an analytical expression for the groundstate in the thermodynamic limit, in which the cavity photons are squeezed by the light-matter coupling. In addition, we derive analytical expressions for the electronic single-particle spectral function and optical conductivity. We unveil quantum Floquet engineering signatures in these dynamical response functions, such as analogs to dynamical localization and replica side bands, complementing paradigmatic classical Floquet engineering results. Strikingly, the Drude weight in the optical conductivity of the electrons is partially suppressed by the presence of a single cavity mode through an induced electron-electron interaction.

Authors 7

1. Christian Eckhardt Aachen Institut für Theorie der Statistischen Physik

   Center for Free-Electron Laser Science · Max Planck Institute for the Structure and Dynamics of Matter · RWTH Aachen University

   Affiliation as printed

   Institut für Theorie der Statistischen Physik, RWTH Aachen University and JARA-Fundamentals of Future Information Technology, 52056, Aachen, Germany

   Max Planck Institute for the Structure and Dynamics of Matter, Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761, Hamburg, Germany

2. Giacomo Passetti Aachen Institut für Theorie der Statistischen Physik

   RWTH Aachen University

   Affiliation as printed

   Institut für Theorie der Statistischen Physik, RWTH Aachen University and JARA-Fundamentals of Future Information Technology, 52056, Aachen, Germany

3. Moustafa Othman

   Technische Universität Braunschweig

   Affiliation as printed

   Technische Universität Braunschweig, Institut für Mathematische Physik, Mendelssohnstraße 3, 38106, Braunschweig, Germany

4. Christoph Karrasch

   Technische Universität Braunschweig

   Affiliation as printed

   Technische Universität Braunschweig, Institut für Mathematische Physik, Mendelssohnstraße 3, 38106, Braunschweig, Germany

5. Fabio Cavaliere

   Superconducting and other Innovative Materials and Devices Institute · University of Genoa

   Affiliation as printed

   Dipartimento di Fisica, Universitá di Genova, Via Dodecaneso 33, 16146, Genova, Italy

   SPIN-CNR, Via Dodecaneso 33, 16146, Genova, Italy

6. Michael A. Sentef

   Center for Free-Electron Laser Science · Max Planck Institute for the Structure and Dynamics of Matter

   Affiliation as printed

   Max Planck Institute for the Structure and Dynamics of Matter, Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761, Hamburg, Germany

7. Dante Marvin Kennes corresponding Aachen Institut für Theorie der Statistischen Physik

   Center for Free-Electron Laser Science · Max Planck Institute for the Structure and Dynamics of Matter · RWTH Aachen University

   Affiliation as printed

   Institut für Theorie der Statistischen Physik, RWTH Aachen University and JARA-Fundamentals of Future Information Technology, 52056, Aachen, Germany

   Max Planck Institute for the Structure and Dynamics of Matter, Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761, Hamburg, Germany