A universal approximation for entanglement entropies of equilibrated pure states

Abstract: When a pure state in a non-integrable quantum many-body system is evolved to late times, we expect it to thermalize—that is, we expect its macroscopic properties to resemble those of an equilibrium density matrix. However, the entanglement entropies of such a state must obey certain constraints coming from unitarity, which are not obeyed by an equilibrium density matrix. In this talk, I will explain an approximation method that leads to a simple universal expression for the entanglement entropies of an equilibrated pure state in any quantum many-body system. This expression is independent of the details of the initial state and hence reflects thermalization, while also being manifestly consistent with unitarity. I will also discuss how this method can be applied to equilibrated pure states in gravitational systems, such as those involving black holes, where it can be used to address the information loss paradox of Hawking.

condensed matterchaotic dynamicsexactly solvable and integrable systemsquantum physics

Audience: researchers in the topic

Quantum Chaos 2020 Seminars

Series comments: A series of online talks about topics related to Quantum Chaos in its various forms, including (but not limiting to): Manifestations of chaos in quantum systems, quantum information scrambling, ergodicity and thermalization in closed many-body quantum systems, and quantum simulations of complex quantum dynamics .

Talks given by senior researchers as well as students and postdocs.