How to probe the microscopic onset of irreversibility with ultracold atoms

• Published in: Scientific reports Vol. 9; no. 1; pp. 14169 - 8
• Main Authors: Bürkle, R., Vardi, A., Cohen, D., Anglin, J. R.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.10.2019; Nature Publishing Group
• Subjects: 639/766/119/2791; 639/766/36/1125; 639/766/530/2804; Adiabatic; Cooking; Entropy; Experiments; Humanities and Social Sciences; Hysteresis; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-50608-z

The microscopic onset of irreversibility is finally becoming an experimental subject. Recent experiments on microscopic open and even isolated systems have measured statistical properties associated with entropy production, and hysteresis-like phenomena have been seen in cold atom systems with dissipation ( i . e . effectively open systems coupled to macroscopic reservoirs). Here we show how experiments on isolated systems of ultracold atoms can show dramatic irreversibility like cooking an egg. In our proposed experiments, a slow forward-and-back parameter sweep will sometimes fail to return the system close to its initial state. This probabilistic hysteresis is due to the same non-adiabatic spreading and ergodic mixing in phase space that explains macroscopic irreversibility, but realized without dynamical chaos; moreover this fundamental mechanism quantitatively determines the probability of return to the initial state as a function of tunable parameters in the proposed experiments. Matching the predicted curve of return probability will be a conclusive experimental demonstration of the microscopic onset of irreversibility.