Quantum Thermalization, how does it work?
When you add milk to your coffee you witness the consequences of ergodicity in classical chaotic systems. After a short transient time, the liquid equilibrates soon in an homogeneous brown mixture.
Thermalization and equilibration in quantum mechanics are not so well understood. There is strong numerical evidence that non-integrable quantum systems generally equilibrate into thermal states. Some questions remain open, for example, what are the time-scales for thermalization in quantum systems? Is it possible to use quantum ergodicity to generate quantum states useful in quantum information? How do the laws of thermodynamics emerge in microscopic systems?
Together with Tobias Schaetz' group at University of Freiburg, we have carried out experimental and numerical work to assess some of this questions in a microscopic crystal with 5 trapped ions.
G. Clos, D. Porras, U. Warring, T. Schaez, arXiv:1509.07712 (2015).