Driven Quantum Many-Body Systems at the Critical Point: Heating, Cooling, and Beyond

Abstract: The study of non-equilibrium quantum many-body physics opens the door to new and exciting conceptual questions about thermalization, dynamics, universality and phase transitions beyond traditional condensed matter paradigms.  These questions are strongly motivated by the rapid progress in ultra-cold atoms, trapped ions, superconducting qubits and so on that offer promising experimental platforms to investigate the non-equilibrium dynamics of quantum systems. Current theoretical study of these interesting questions mainly relies on numerical tools, which are limited in their scope in both the system size and the time scale of evolution. It is desirable to find setups for non-equilibrium many-body dynamics that are nontrivial, universal, and exactly solvable.

In this talk, I will introduce our recent progress in a family of time-dependent driven quantum many-body systems at the critical point, with several salient features: (1) There are rich phase diagrams depending on the driving parameters. (2) The dynamics is independent of the underlying microscopic models, and therefore is universal. (3) The driven dynamics is exactly solvable at an arbitrary time. In addition to understanding the fundamental questions such as how entanglement and energy evolve in time during the driving, I will also introduce its application in quantum cooling which opens a promising new route to cooling quantum systems, as well as an efficient way of measuring the entanglement evolution in driven systems.