INPHYNI seminar: Tony Jin

Seminars of the Institut de Physique de Nice,
new permanent members series

Abstract:
Almost by definition, the stationary statistical properties of an isolated chaotic many-body system will be well described by the maximally entropic, microcanonical
ensemble. On the other hand, a system undergoing measurements from an external observer will eventually tend towards a state of very low entropy (the more precise the measurements, the lower the entropy). Now what happens if one simultaneously lets the system evolve and perform measurements? We will see that, perhaps surprisingly, both in the quantum and the classical world, phase transitions with information-related quantities as order parameter (e.g. entanglement entropy) may occur. In particular, I will present a simple yet non trivial model where this occurs, a single discrete classical random walker undergoing continuous measurements. We will see that, for this example, much of the phenomenology can be understood through connections with the physics of surface growth, in particular, the Kardar-Parisi- Zhang equation. If time allows, I will also discuss the quantum version of this minimal model.

The original paper on MiPT: Measurement-Induced Phase Transitions in the Dynamics of Entanglement
Skinner, Ruhman, Nahum, PRX (2019)

Our work with David G. Martin that I will discuss :
Kardar-Parisi-Zhang Physics and Phase Transition in a Classical Single Random Walker under Continuous Measurement Jin, Martin, PRL (2022)