1. understanding quantum chaos through adiabatic transforamtions

Anatoli Polkovnikov

University of Boston, USA

24 February 2022 Thu 10 am

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

In the first part of the talk I will introduce the notion of the adiabatic gauge potential as a generator of continuous adiabatic transformations and how we can use its norm (aka fidelity susceptibility or the quantum geometric tensor) as a probe distinguishing chaotic and integrable systems. I will also discuss that in generic many-body systems the integrable and ergodic phases are generically separated by a universal buffer regime characterized by the maximum possible sensitivity of eigenstates (or the maximum fidelity susceptibility) to small changes of the Hamiltonian. In the second part of the talk I will discuss applications of this probe to disordered systems and give an evidence that there is no true many body localization in the thermodynamic limit.