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arXiv · 1810.00051

New equilibrium ensembles for isolated quantum systems

Fabio Anza
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Abstract

The unitary dynamics of isolated quantum systems does not allow a pure state to thermalize. Because of that, if an isolated quantum system equilibrates, it will do so to the predictions of the so-called "diagonal ensemble" $\rho_{DE}$. Building on the intuition provided by Jaynes' maximum entropy principle, in this paper we present a novel technique to generate progressively better approximations to $\rho_{DE}$. As an example, we write down a hierarchical set of ensembles which can be used to describe the equilibrium physics of small isolated quantum systems, going beyond the "thermal ansatz" of Gibbs ensembles.

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Fabio Anza. 2018-09-28. New equilibrium ensembles for isolated quantum systems. https://doi.org/10.3390/e20100744

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