Experimental investigation of relaxation for far-from equilibrium quantum many body system

Abstract

The study of quantum systems far from equilibrium has become a cornerstone in the development of emerging quantum technologies. Real-world quantum devices, such as quantum computers, simulators, and sensors, inevitably operate under conditions of driving, dissipation, and decoherence. Consequently, non-equilibrium dynamics are not an exception but a defining feature of these systems. A fundamental understanding of how quantum systems relax, thermalize, or avoid thermalization is essential for stabilizing coherence, extending memory lifetimes, and protecting entanglement. Experimental observations of turbulent Bose–Einstein condensates (BECs) have demonstrated the existence of distinct relaxation pathways. Depending on system conditions, a turbulent BEC may evolve toward a recondensed coherent state or decay into a thermal, non-degenerate quantum fluid. This evolution proceeds through well-defined dynamical stages, characterized by complex vortex interactions, energy cascades, and the redistribution of coherence across scales. Understanding these pathways provides critical insight into the mechanisms governing quantum turbulence and the emergence of order from strongly non-equilibrium states, offering new opportunities to control and harness quantum coherence in realistic environments.