Upper bounds on mixing rates
Abstract
We prove upper bounds on the rate, called "mixing rate", at which the von Neumann entropy of the expected density operator of a given ensemble of states changes under non-local unitary evolution. For an ensemble consisting of two states, with probabilities of p and 1-p, we prove that the mixing rate is bounded above by 4\sqrt{p(1-p)} for any Hamiltonian of norm 1. For a general ensemble of states with probabilities distributed according to a random variable X and individually evolving according to any set of bounded Hamiltonians, we conjecture that the mixing rate is bounded above by a Shannon entropy of a random variable X. For this general case we prove an upper bound that is independent of the dimension of the Hilbert space on which states in the ensemble act.
Cite
@article{arxiv.1302.3865,
title = {Upper bounds on mixing rates},
author = {Elliott H. Lieb and Anna Vershynina},
journal= {arXiv preprint arXiv:1302.3865},
year = {2013}
}