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arXiv · 1302.3865

Upper bounds on mixing rates

Elliott H. Lieb·Anna Vershynina
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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.

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Elliott H. Lieb, Anna Vershynina. 2013-02-15. Upper bounds on mixing rates. https://arxiv.org/abs/1302.3865

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