Experimental Observation of a Time-Driven Phase Transition in Quantum Chaos

Clément Hainaut (1) , Ping Fang (2) , Adam Rançon (1) , Jean-François Clément (1) , Pascal Szriftgiser (1) , Jean-Claude Garreau (1) , Chushun Tian (1) , Radu Chicireanu (1)

1 PhLAM - Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523
2 THU - Tsinghua University [Beijing]

We report the first experimental observation of the time-driven phase transition in a canonical quantum chaotic system, the quantum kicked rotor. The transition bears a firm analogy to a thermodynamic phase transition, with the time mimicking the temperature and the quantum expectation of the rotor’s kinetic energy mimicking the free energy. The transition signals a sudden change in the system’s memory behavior: before the critical time, the system undergoes chaotic motion in phase space and its memory of initial states is erased in the course of time; after the critical time, quantum interference enhances the probability for a chaotic trajectory to return to the initial state, and thus the system’s memory is recovered.

Mots clés: Nonlinear Dynamics; Fluid Dynamics; Classical Optics

Domaines: Physique Quantique [quant-ph]

Clément Hainaut, Ping Fang, Adam Rançon, Jean-François Clément, Pascal Szriftgiser, et al.. Experimental Observation of a Time-Driven Phase Transition in Quantum Chaos. Physical Review Letters, 2018, 121 (13), pp.134101. ⟨10.1103/PhysRevLett.121.134101⟩. ⟨hal-01744050⟩