Observing the quantum Mpemba effect in a quantum processor

B. Vermersch, Quobly & Université Grenoble Alpes (on leave)


When a system is brought out of equilibrium, it may exhibit phenomena that defy conventional wisdom. One particularly puzzling example is the Mpemba effect, firstly described as the phenomenon where hot water freezes faster than cold water. While the Mpemba effect remains partly unexplained but also difficult to reproduce, quantum processors were recently used to experimentally observe a "quantum" Mpemba effect. While classical and quantum Mpemba effects are a priori not related, this experiment result reveals a surprising aspect of thermalization in quantum systems. My presentation will begin with a short introduction on the classical Mpemba effect. I will then introduce quantum processors, which are systems of individually controlled quantum particles that interact in a programmable manner. This will allow me to describe the experimental sequence that led to the observation of the quantum Mpemba effect.

L. Kh. Joshi et al., Observing the Quantum Mpemba Effect in Quantum Simulations, Phys. Rev. Lett. 133, 010402 (2024).