## Probing non-thermal density fluctuations in the one-dimensional Bose gas

Jacopo De Nardis, Miłosz Panfil, Andrea Gambassi, Leticia F. Cugliandolo, Robert Konik, Laura Foini

SciPost Phys. 3, 023 (2017) · published 27 September 2017

- doi: 10.21468/SciPostPhys.3.3.023
- Submissions/Reports

### Abstract

Quantum integrable models display a rich variety of non-thermal excited states with unusual properties. The most common way to probe them is by performing a quantum quench, i.e., by letting a many-body initial state unitarily evolve with an integrable Hamiltonian. At late times, these systems are locally described by a generalized Gibbs ensemble with as many effective temperatures as their local conserved quantities. The experimental measurement of this macroscopic number of temperatures remains elusive. Here we show that they can be obtained by probing the dynamical structure factor of the system after the quench and by employing a generalized fluctuation-dissipation theorem that we provide. Our procedure allows us to completely reconstruct the stationary state of a quantum integrable system from state-of-the-art experimental observations.

### Cited by 10

### Ontology / Topics

See full Ontology or Topics database.### Authors / Affiliations: mappings to Contributors and Organizations

See all Organizations.-
^{1 }^{2 }Jacopo De Nardis, -
^{3 }Milosz Panfil, -
^{4 }Andrea Gambassi, -
^{5 }Leticia Cugliandolo, -
^{6 }Robert Konik, -
^{2 }Laura Foini

^{1}Centre National de la Recherche Scientifique / French National Centre for Scientific Research [CNRS]^{2}École Normale Supérieure [ENS]^{3}Uniwersytet Warszawski / University of Warsaw [UW]^{4}Istituto Nazionale di Fisica Nucleare (presso la SISSA) / National Institute of Nuclear Physics (at SISSA) [INFN at SISSA]^{5}Laboratoire de Physique Théorique et Hautes Energies / Laboratory of Theoretical and High Energy Physics [LPTHE]^{6}Brookhaven National Laboratory [BNL]