Nonlocality as the source of purely quantum dynamics of BCS superconductors
arXiv:2208.07320 · doi:10.1103/PhysRevB.106.104513
Abstract
We show that the classical (mean-field) description of far from equilibrium superconductivity is exact in the thermodynamic limit for local observables but breaks down for global quantities, such as the entanglement entropy or Loschmidt echo. We do this by solving for and comparing exact quantum and exact classical long-time dynamics of a BCS superconductor with interaction strength inversely proportional to time and evaluating local observables explicitly. Mean field is exact for both normal and anomalous averages (superconducting order) in the thermodynamic limit. However, for anomalous expectation values, this limit does not commute with adiabatic and strong coupling limits and, as a consequence, their quantum fluctuations can be unusually strong. The long-time steady state of the system is a gapless superconductor whose superfluid properties are only accessible through energy resolved measurements. This state is nonthermal but conforms to an emergent generalized Gibbs ensemble. Our study clarifies the nature of symmetry-broken many-body states in and out of equilibrium and fills a crucial gap in the theory of time-dependent quantum integrability.
arXiv comment30 pages, 10 figures, new title
References in corpus (57)
- Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
- Nonequilibrium dynamics of closed interacting quantum systems
- Relaxation in a Completely Integrable Many-Body Quantum System: An Ab Initio Study of the Dynamics of the Highly Excited States of Lattice Hard-Core Bosons
- Entanglement entropy in free quantum field theory
- Time evolution of local observables after quenching to an integrable model
- Spectroscopy of discrete energy levels in ultrasmall metallic grains
- Higgs Amplitude Mode in BCS Superconductors NbTiN induced by Terahertz Pulse Excitation
- Resonantly-paired fermionic superfluids
- Quenching the Anisotropic Heisenberg Chain: Exact Solution and Generalized Gibbs Ensemble Predictions
- Solitons and Rabi Oscillations in a Time-Dependent BCS Pairing Problem
- Hard-core bosons on optical superlattices: Dynamics and relaxation in the superfluid and insulating regimes
- Nonequilibrium Transport in Quantum Impurity Models (Bethe-Ansatz for open systems)
- Synchronization in the BCS Pairing Dynamics as a Critical Phenomenon
- Exploring dynamical phase transitions with cold atoms in an optical cavity
- Exactly-Solvable Models Derived from a Generalized Gaudin Algebra
- Theory of Anderson pseudospin resonance with Higgs mode in superconductors
- Dynamical vanishing of the order parameter in a fermionic condensate
- Exact diagonalization: the Bose-Hubbard model as an example
- Dynamical transitions and quantum quenches in mean-field models
- Quantum quenches, dynamical transitions and off-equilibrium quantum criticality
- Nonequilibrium dynamics and thermodynamics of a degenerate Fermi gas across a Feshbach resonance
- Nonequilibrium Cooper pairing in the nonadiabatic regime
- Solution for the dynamics of the BCS and central spin problems
- A Mini-Introduction To Information Theory
- Observation of a Transition Between Dynamical Phases in a Quantum Degenerate Fermi Gas
- Off-Shell Bethe Ansatz Equation and N-point Correlators in the SU(2) WZNW Theory
- Quantum quenches from integrability: the fermionic pairing model
- Quantum quench in a p + i p superfluid: Winding numbers and topological states far from equilibrium
- Quantum quench phase diagrams of an s-wave BCS-BEC condensate
- Thermalization and canonical typicality in translation-invariant quantum lattice systems
- Energy Resolved Supercurrent between two superconductors
- Large N limit of the exactly solvable BCS model: analytics versus numerics
- Nonequilibrium dynamics of weakly and strongly paired superconductors
- Quench-induced Floquet topological p-wave superfluids
- The Current Carried by Bound States of a Superconducting Vortex
- Bethe Ansatz approach to quench dynamics in the Richardson model
- Origin of the slow growth of entanglement entropy in long-range interacting spin systems
- Signatures of nonadiabatic BCS state dynamics in pump-probe conductivity
- Integrable time-dependent quantum Hamiltonians
- Dynamics of the BCS-BEC crossover in a degenerate Fermi gas
- Twisting Anderson pseudospins with light: Quench dynamics in THz-pumped BCS superconductors
- Strong Coupling Expansion for the Pairing Hamiltonian
- Finite Size Corrections for the Pairing Hamiltonian
- Absence of thermalization for systems with long-range interactions coupled to a thermal bath
- Integrable time-dependent Hamiltonians, solvable Landau-Zener models and Gaudin magnets
- Cooper pair turbulence in atomic Fermi gases
- A cavity-QED quantum simulator of dynamical phases of a BCS superconductor
- Quantum integrability in the multistate Landau-Zener problem
- Spectroscopic signatures of nonequilibrium pairing in atomic Fermi gases
- Non-equilibrum dynamics in the strongly excited inhomogeneous Dicke model
- Generalized microcanonical and Gibbs ensembles in classical and quantum integrable dynamics
- Quantum annealing and thermalization: insights from integrability
- Nonequilibrium pairing instability in ultracold Fermi gases with population imbalance
- Exact out-of-equilibrium central spin dynamics from integrability
- Dynamics of emergent Cooper pairing at finite temperatures
- Towards a Non-equilibrium Bethe ansatz for the Kondo Model
- Dissipationless BCS Dynamics with Large Branch Imbalance