TITLE : Many-body localization, quantum coherence and discrete time crystals

ABSTRACT :

Many-body localization (MBL) is a fascinating phenomenon which lies at the interface of quantum condensed matter physics, quantum information and quantum statistical physics. MBL. which is realized in interacting quantum systems which are highly disordered, is an interesting and unusual phenomenon in many aspects. An isolated quantum system in the MBL phase is non-ergodic and hence, challenges the basic foundations of quantum statistical physics. Local observables in the MBL phase do not thermalize leading to the violation of eigenstate thermalization hypothesis. This results in a rich behaviour of entanglement entropy and a long time memory of the initial state in local observables. In this talk I will first describe the current status of MBL followed by our recent related works mainly focusing on some of the interesting applications of MBL. I will discuss exact trade-off relations that we have proved between quantum coherence and a measure of localization and many-body localization. I will show that though the full system loses coherence in the MBL phase, coherence of a subsystem can increase with the combined effect of disorder and interactions. I will also discuss periodically driven MBL systems which can host discrete time -crystal, an unusual non-equilibrium phase of matter which breaks discrete time translation symmetry and has potential applications in quantum memory, quantum sensing and metrology.

MEETING DETAILS :

Joining Link: https://meet.google.com/mtd-thrv-hfn

Speaker: Prof. Arti Garg, Theory Division, Saha Institute of Nuclear Physics, Kolkata

Venue: A1-NKN, South Campus, IIT Mandi

Date and Time: Monday, June 2, 2025, 04:00 pm (IST)