The emergence of relaxation in unitarily evolving systems can be seen as a paradox, but not once the distinction between local and global dynamics is considered. Here, the authors use photons in an integrated optical interferometer to show that, for a system evolving unitarily on a global level, single-mode measurements converge to those of a thermal state.
- F. H. B. Somhorst
- R. van der Meer
- J. J. Renema
