Non-thermal quantum phase transitions

Abstract

We report a kind of quantum phase transition which takes place in isolated quantum systems with non-thermal equilibrium states and an extra symmetry that commutes with the Hamiltonian for any values of the system parameters. A critical energy separates two different phases, one in which the symmetry is broken. This critical behavior is ruled out as soon as the system is put in contact with a thermal bath. The critical point is crossed when a sufficent amount of work is performed on the system, keeping it isolated from the environment. Different phases are identified by means of an order parameter, which is only different from zero in the symmetry-breaking phase. The behavior of the system near the critical point is determined by a set of critical exponents. We illustrate this phenomenon by means of numerical calculations in three different two-level systems.

References in corpus (8)

• Thermalization and its mechanism for generic isolated quantum systems
• Non-equilibrium coherence dynamics in one-dimensional Bose gases
• Excited state quantum phase transitions in many-body systems
• Exact spectrum of the Lipkin-Meshkov-Glick model in the thermodynamic limit and finite-size corrections
• Excited-State Quantum Phase Transitions in Dicke Superradiance Models
• Impact of Quantum Phase Transitions on Excited Level Dynamics
• Excited-state phase transition leading to symmetry-breaking steady states in the Dicke model
• A scalar two-level boson model to study the IBM phase diagram in the Casten triangle

Cited by in corpus (24)

• Excited-state quantum phase transitions
• Entropy, chaos and excited-state quantum phase transitions in the Dicke model
• From thermal to excited-state quantum phase transitions ---the Dicke model
• Dynamical and excited-state quantum phase transitions in collective systems
• Excited-state quantum phase transitions in spinor Bose-Einstein condensates
• Irreversible processes without energy dissipation in an isolated Lipkin-Meshkov-Glick model
• Theory of dynamical phase transitions in quantum systems with symmetry-breaking eigenstates
• Constant of motion identifying excited-state quantum phases
• Signatures of excited state quantum phase transitions in quantum many body systems: Phase space analysis
• Characterizing the dynamical phase diagram of the Dicke model via classical and quantum probes
• Identifying and harnessing dynamical phase transitions for quantum-enhanced sensing
• Quantum phase transitions of atom-molecule Bose mixtures in a double-well potential
• Work statistics and symmetry breaking in an excited state quantum phase transition
• Thermodynamics and Superradiant Phase Transitions in a three-level Dicke Model
• Mechanism of dynamical phase transitions: The complex-time survival amplitude
• Characterizing the excited-state quantum phase transition via the dynamical and statistical properties of the diagonal entropy
• Critical quasienergy states in driven many-body systems
• Mixed eigenstates in the Dicke model: Statistics and power-law decay of the relative proportion in the semiclassical limit
• Excited state quantum phase transition and Loschmidt echo spectra in a spinor Bose-Einstein condensate
• Excited-State Phase Diagram of a Ferromagnetic Quantum Gas
• General theory for discrete symmetry-breaking equilibrium states
• Quantum information scrambling in adiabatically-driven critical systems
• Chaos, thermalization and breakdown of quantum-classical correspondence in a collective many-body system
• Energy cat states induced by a parity-breaking excited-state quantum phase transition