Thema der Dissertation:
Thermalization in Quantum Many-Body Physics
Thermalization in Quantum Many-Body Physics
Abstract: How isolated quantum many-body systems approach thermal equilibrium has remained a central problem since the beginning of quantum mechanics. This problem has been studied from a variety of perspectives. Quantum chaos provides a natural framework for understanding the relaxation of subsystems to Gibbs states, while random matrix theory has served as an effective tool for modeling such behavior. More recently, ideas from quantum information theory have offered new conceptual insights, and developments in non-equilibrium dynamics have introduced novel tools and settings for studying thermalization. In this talk, I will present the results of my thesis that are centered around the topic of thermalization in quantum many body physics. I will rigorously establish infinite-temperature thermalization and equilibration for simple operators evolving under Hamiltonians with non-degenerate energy gaps. This is demonstrated for two classes of initial states: random tensor network states and quantum circuits associated with the dynamics of the kicked Ising model with subsystem measurements. The proof employs tools from random matrix theory, which are naturally applicable in the context of random tensor networks, and extends to measured kicked Ising circuits due to an emergent randomness structure. Finally, I will demonstrate how methods of free probability theory will be applied to the study of out-of-time-order correlators, and allow one to derive bounds on ensemble complexity in the large-dimension limit of random matrices and providing an alternative description of scrambling and late-time dynamics in controlled quantum many-body systems with structured randomness such as a brickwork random quantum circuit.
Time & Location
Sep 25, 2026 | 03:30 PM
Hörsaal A (1.3.14)
(Fachbereich Physik, Arnimallee 14, 14195 Berlin)