title: Quench echo and work statistics in integrable quantum field theories.
abstract: We propose a boundary thermodynamic Bethe ansatz calculation technique to obtain the Loschmidt echo and the statistics of the work done when a global quantum quench is performed on an integrable quantum field theory. We derive an analytic expression for the lowest edge of the probability density function and find that it exhibits universal features, in the sense that its scaling form depends only on the statistics of excitations. We perform numerical calculations on the sinh-Gordon model, a deformation of the free boson theory, and we obtain that by turning on the interaction the density function develops fermionic properties. The calculations are facilitated by a previously unnoticed property of the thermodynamic Bethe ansatz construction.
authors.affiliation: SISSA and INFN, Sezione Trieste Via Bonomea 265, 34136 Trieste, Italy and Budapest University of Technology and Economics Budafoki ut 8, 1111 Budapest, Hungary.
authors.forename: T
authors.initials: T
authors.lastname: Pálmai
authors.affiliation: SISSA and INFN, Sezione Trieste Via Bonomea 265, 34136 Trieste, Italy and Dipartimento di Fisica dell'Università di Pisa and INFN, Sezione Pisa 56127 Pisa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Sotiriadis