Work on equilibration in PRL

Equilibration in closed quantum many-body systems is one of the puzzles of quantum theory increasingly well understood in recent years

Equilibration in closed quantum many-body systems is one of the puzzles of quantum theory increasingly well understood in recent years

One of the outstanding problems in non-equilibrium physics is to precisely understand when and how physically relevant observables in many-body systems equilibrate under unitary time evolution. General equilibration results show that equilibration is generic provided that the initial state has overlap with sufficiently many energy levels. But results not referring to typicality which show that natural initial states actually fulfill this condition are lacking.

In this work, published in the Physical Review Letters, we present stringent results for equilibration for systems in which Renyi entanglement entropies in energy eigenstates with finite energy density are extensive for at least some, not necessarily connected, sub-system. Our results reverse the logic of common arguments, in that we derive equilibration from a weak condition akin to the eigenstate thermalization hypothesis, which is usually attributed to thermalization in systems that are assumed to equilibrate in the first place. We put the findings into the context of studies of many-body localization and many-body scars.

This work has received significant attention, see, e.g., the Viewpoint in Physics 12, 123

News from Nov 20, 2019

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