Quantum kinetics of ultracold fermions coupled to an optical resonator

Abstract

We study the far-from-equilibrium statistical mechanics of periodically driven fermionic atoms in a lossy optical resonator. We show that the interplay of the Fermi surface with cavity losses leads to sub-natural cavity linewidth narrowing, squeezed light, and out-of-equilibrium quantum statistics of the atoms. Adapting the Keldysh approach, we set-up and solve a quantum kinetic Boltzmann equation in a systematic $1/N$ expansion with $N$ the number of atoms. In the strict thermodynamic limit $N,V\to \infty$, $N/V=\text{const.}$ we find the atoms (fermions or bosons) remain immune against cavity-induced heating or cooling. At next-to-leading order in $1/N$, we find a "one-way thermalization" of the atoms determined by cavity decay. We argue that, in absence of an equilibrium fluctuation-dissipation relation, the long-time limit $\Delta t\to \infty$ does not commute with the thermodynamic limit $N\to \infty$, such that for the physically relevant case of large but finite $N$, the dynamics ultimately becomes strongly coupled, especially close to the superradiance phase transition.

41 pages. Bosons are also treated

References in corpus (16)

• Statistical mechanics and dynamics of solvable models with long-range interactions
• Cold atoms in cavity-generated dynamical optical potentials
• Bose-Einstein condensation of photons in an optical microcavity
• Strong atom-field coupling for Bose-Einstein condensates in an optical cavity on a chip
• Cavity Opto-Mechanics with a Bose-Einstein Condensate
• Roton-type mode softening in a quantum gas with cavity-mediated long-range interactions
• Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion
• Keldysh approach for non-equilibrium phase transitions in quantum optics: beyond the Dicke model in optical cavities
• Self-organization of a Bose-Einstein condensate in an optical cavity
• Ultracold atoms in optical lattices generated by quantized light fields
• Bose-glass phases of ultracold atoms due to cavity backaction
• Atom-light crystallization of BECs in multimode cavities: Nonequilibrium classical and quantum phase transitions, emergent lattices, supersolidity, and frustration
• Steering matter wave superradiance with an ultra-narrowband optical cavity
• Self-Organization Threshold Scaling for Thermal Atoms Coupled to a Cavity
• Damping of quasiparticles in a Bose-Einstein condensate coupled to an optical cavity
• Self-ordering dynamics of ultracold atoms in multicolored cavity fields

Cited by in corpus (20)

• Cavity QED with Quantum Gases: New Paradigms in Many-Body Physics
• Long-range interacting quantum systems
• A Superradiant Topological Peierls Insulator inside an Optical Cavity
• Universality in driven open quantum matter
• Dicke phase transition without total spin conservation
• Long-range photon fluctuations enhance photon-mediated electron pairing and superconductivity
• Many-body non-Hermitian skin effect under dynamic gauge coupling
• Dicke transition in open many-body systems determined by fluctuation effects
• Generating Functional Approach for Spontaneous Coherence in Semiconductor Electron-Hole-Photon Systems
• Multimode-polariton superradiance via Floquet engineering
• Fluctuation-Induced Bistability of Fermionic Atoms Coupled to a Dissipative Cavity
• Laser-painted cavity-mediated interactions in a quantum gas
• Nonthermal electron-photon steady states in open cavity quantum materials
• Master Equation for a Quantum Gas of Polarizable Particles in Cavities
• Controlling Collective Phenomena Via the Quantum State of Interaction-Mediators: Changing the Criticality of Photon-Mediated Superconductivity Via Fock States of Light
• The Single Particle Excitation Spectrum of Degenerate Fermi gases in a ring cavity
• Tuning Density and Spin Ordering of Degenerate Fermi Gases in an Optical Cavity
• The fate of the Fermi surface coupled to a single-wave-vector cavity mode
• The role of atomic interactions in cavity-induced continuous time crystals
• Paramagnetic phases of strongly correlated ultracold fermions coupled to an optical cavity