Title: Quantum sensing via many-body scars

Abstract: Just as a hot cup of tea on your desk will eventually cool to room temperature, often a large isolated quantum system that is initially out-of-equilibrium will eventually thermalise. This process is the enemy of quantum technologies, since it tends to erase much of the accessible quantum information that is stored in the system state. Recently, a new mechanism to slow down, or even avoid thermalisation in isolated quantum systems was discovered theoretically and observed experimentally, and was given the name “quantum many-body scarring”. It is natural to ask: can this new mechanism be exploited to protect quantum technologies against thermalisation? Here, I address this question from the perspective of quantum sensing (the quantum technology that aims for ultra-precise estimation of physical parameters). I show that many-body scars can indeed be exploited for sensing that is robust against certain strong interactions that might usually be expected to result in thermalisation. In the ideal case, the sensor is completely shielded from thermalisation despite the strong interactions. 

Reference: PRX Quantum 2, 020330 (2021)

Talk – Video

Talk – Slides