Theoretical Physics Colloquium

Onsets of many-body chaos due to breaking integrability

by Dr. Vir B. Bulchandani (Princeton University, USA)

Tuesday, April 19, 2022 from to (Asia/Kolkata)
at Zoom : https://zoom.us/j/94195941535?pwd=RWRZU09sQWxRWEVneXNzMVp2NFVxdz09 Meeting ID: 941 9594 1535 Passcode: 958967
Description
Generic perturbations of an integrable system lead to chaos. How they lead to chaos in the classical setting has been understood for decades and is captured by the Kolmogorov-Arnold-Moser theorem. No such result exists for quantum systems; moreover, the scaling of the threshold to chaos with system size is not well understood even classically. We propose some answers to these questions for quantum many-body systems, arguing that the onset of chaos can be understood as a Fock-space delocalization process. We also discuss incomplete thermalization when integrability is broken by an external trapping potential, which is relevant to "quantum Newton's cradle" experiments on ultracold atoms.