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Seminarium om teoretisk fysik - Yunxiang Liao

Science and Information Technology

This is part of a seminar series for students and researchers interested in theoretical physics and applied mathematics. Listen to Yunxiang Liao (KTH) during the seminar "Quantum chaos and thermalization in random quantum circuits".

Seminar,
Webinar
Date
30 Nov 2023
Time
15:15 - 16:15
Location
PJ-salen och via Zoom

Quantum chaos and thermalization in random quantum circuits

Yunxiang Liao (KTH)

Abstract

The question of how statistical mechanics behavior emerges from the unitary dynamics of isolated quantum interacting systems can be well understood using an assumption about the structure of the energy eigenstates, known as the eigenstate thermalization hypothesis (ETH). ETH is a natural extension of the random matrix theory (RMT) and establishes a connection between quantum thermalization and the notion of quantum chaos. In this talk, I will present our analytical studies on quantum chaos and eigenstate thermalization in a large family of random quantum circuits. A field theoretical approach is used to investigate the statistical properties of quasienergy eigenstates and eigenvalues, and this method can be generalized to explore other fundamental features of various quantum circuit models. Our calculation of energy level correlation function shows that all the random quantum circuits under consideration exhibit the universal RMT level statistics, a defining property of quantum chaos. Our analysis of eigenstate correlation function provides analytical support for ETH and also suggests that the spectral form factor, a measure of level statistics, determines the time dependence of the approach to thermal equilibrium. 

The seminar is held in hybrid form

Participate on campus or via Zoom.

On campus: PJ Lecture Hall
Zoom link: https://gu-se.zoom.us/j/64681043702

Read more about the seminar series

Theoretical Physics Seminar