Many-Body Localisation: Breakdown of Thermalisation in Many-Body Quantum Systems

Dr Arijeet Pal (UCL)

The laws of thermodynamics are known to apply to a wide range of natural phenomena from electrons inside solids to stars in distant galaxies. In recent years it has been discovered that thermodynamics can breakdown in isolated, interacting quantum systems with disorder, a phenomena known as many-body localisation (MBL). These systems fail to act as their own heat bath and exhibit quantum coherent properties even at a finite energy density above the ground state. 

 In this talk I will give an overview of our current understanding of the phenomena and the open questions in the field. I will discuss how MBL opens the way to protect exotic forms of order like topological order and time-crystallinity in highly excited quantum states. Furthermore, I will describe an efficient  description of MBL phases of matter using shallow quantum circuits.