Quantum quenches from an excited state
- URL: http://arxiv.org/abs/2304.02314v2
- Date: Fri, 11 Aug 2023 08:46:49 GMT
- Title: Quantum quenches from an excited state
- Authors: Gesualdo Delfino and Marianna Sorba
- Abstract summary: We extend the theory of quantum quenches to the case in which before the quench the system is in an excited state.
Oscillations staying undamped within the accessible time interval, far beyond the perturbative time scale, are nowadays observed in numerical simulations.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Determining the role of initial conditions in the late time evolution is a
key issue for the theory of nonequilibrium dynamics of isolated quantum
systems. Here we extend the theory of quantum quenches to the case in which
before the quench the system is in an excited state. In particular, we show
perturbatively in the size of the quench (and for arbitrarily strong
interactions among the quasiparticles) that persistent oscillations of
one-point functions require the presence of a one-quasiparticle contribution to
the nonequilibrium state, as originally shown in [J. Phys. A 47 (2014) 402001]
for the quenches from the ground state. Also in the present case, we argue that
the results generically have nonperturbative implications. Oscillations staying
undamped within the accessible time interval, far beyond the perturbative time
scale, are nowadays observed in numerical simulations.
Related papers
- Quenching from superfluid to free bosons in two dimensions: entanglement, symmetries, and quantum Mpemba effect [0.0]
We study the non-equilibrium dynamics of bosons in a two-dimensional optical lattice after a sudden quench from the superfluid phase to the free-boson regime.
arXiv Detail & Related papers (2024-10-18T09:00:01Z) - On unitary time evolution out of equilibrium [0.0]
We show how the one-point functions of local operators depend on the oscillations of the expansion of the nonequilibrium state.
We show how, in the case of small quenches, the structure of the general results simplifies and reproduces that known perturbatively.
arXiv Detail & Related papers (2024-03-20T10:30:01Z) - Real-time dynamics of false vacuum decay [49.1574468325115]
We investigate false vacuum decay of a relativistic scalar field in the metastable minimum of an asymmetric double-well potential.
We employ the non-perturbative framework of the two-particle irreducible (2PI) quantum effective action at next-to-leading order in a large-N expansion.
arXiv Detail & Related papers (2023-10-06T12:44:48Z) - Universality of critical dynamics with finite entanglement [68.8204255655161]
We study how low-energy dynamics of quantum systems near criticality are modified by finite entanglement.
Our result establishes the precise role played by entanglement in time-dependent critical phenomena.
arXiv Detail & Related papers (2023-01-23T19:23:54Z) - Indication of critical scaling in time during the relaxation of an open
quantum system [34.82692226532414]
Phase transitions correspond to the singular behavior of physical systems in response to continuous control parameters like temperature or external fields.
Near continuous phase transitions, associated with the divergence of a correlation length, universal power-law scaling behavior with critical exponents independent of microscopic system details is found.
arXiv Detail & Related papers (2022-08-10T05:59:14Z) - Metastable discrete time-crystal resonances in a dissipative central
spin system [0.0]
Generalizing the theory of metastability in open quantum systems, we develop an effective description for the evolution within a long-lived metastable subspace.
Our study links to timely questions concerning emergent collective behavior in the 'prethermal' stage of a dissipative quantum many-body evolution.
arXiv Detail & Related papers (2022-05-23T12:27:09Z) - Late-time critical behavior of local string-like observables under
quantum quenches [12.815619486162594]
In recent times it has been observed that signatures of equilibrium quantum criticality surprisingly show up in many-body systems far from equilibrium.
We develop a method to probe ground state critical physics through nonequilibrium post-quench dynamics.
Our results can also be used to explain critical signatures in post-quench domain formation, seen in a recent experiment with trapped ion quantum simulators.
arXiv Detail & Related papers (2022-04-30T08:35:11Z) - Observation of Time-Crystalline Eigenstate Order on a Quantum Processor [80.17270167652622]
Quantum-body systems display rich phase structure in their low-temperature equilibrium states.
We experimentally observe an eigenstate-ordered DTC on superconducting qubits.
Results establish a scalable approach to study non-equilibrium phases of matter on current quantum processors.
arXiv Detail & Related papers (2021-07-28T18:00:03Z) - Analog cosmological reheating in an ultracold Bose gas [58.720142291102135]
We quantum-simulate the reheating-like dynamics of a generic cosmological single-field model in an ultracold Bose gas.
Expanding spacetime as well as the background oscillating inflaton field are mimicked in the non-relativistic limit.
The proposed experiment has the potential of exploring the evolution up to late times even beyond the weak coupling regime.
arXiv Detail & Related papers (2020-08-05T18:00:26Z) - Quantum Zeno effect appears in stages [64.41511459132334]
In the quantum Zeno effect, quantum measurements can block the coherent oscillation of a two level system by freezing its state to one of the measurement eigenstates.
We show that the onset of the Zeno regime is marked by a $textitcascade of transitions$ in the system dynamics as the measurement strength is increased.
arXiv Detail & Related papers (2020-03-23T18:17:36Z) - Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit.
We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront.
The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
arXiv Detail & Related papers (2020-03-09T21:27:02Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.