An educated review of "Quantum work statistics, Loschmidt echo and information scrambling".
Autor
González Padrón, EduardoFecha
2020Resumen
The formulation of quantum work statistics as a dynamical problem through the
Loschmidt echo is at the heart of this work. An introduction to each of these
concepts is presented together with the notion of information scrambling, which
extends the scope of this work to areas such as quantum chaos or even black hole
physics. Using the paper of A. Chenu et al. [1] as the guidelines, we first show
that the work statistics associated with an arbitrary driving protocol of an isolated quantum system in a generic initial state is equivalent to the Loschmidt echo
dynamics of a purified density matrix in an enlarged Hilbert space. When the initial state is thermal, the purification leads to a thermofield double state, which is
used to describe eternal black holes through the AdS/CFT correspondence, often
argued to be the fastest information scramblers. The field of quantum chaotic
systems is shown to emerge naturally from the previous content, and a full description of it in terms of Random Matrix Theory is also presented. Numerical and
analytical results are finally obtained for the quantities introduced after imposing
time-reversal symmetry in our problem, hence selecting the Gaussian Orthogonal
Ensemble as the framework within we shall take our averages.