We detail the experimental observation of the non-equilibrium many-body phenomenon prethermalization.We study the dynamics of a rapidly and coherently split one-dimensional Bose gas.An analysis based on the use of full quantum mechanical probability distributions of matter wave interference contrast reveals that the system evolves toward a quasi-steady state.This state, which can be characterized by an effective temperature, is not the final thermal equilibrium state.We compare the evolution of the system to an integrable Tomonaga-Luttinger liquid model, and show that the system dephases to a prethermalized state rather than undergoing thermalization toward a final thermal equilibrium state.
We detail the experimental observation of the non-equilibrium many-body phenomenon prethermalization.We study the dynamics of a rapidly and coherently split one-dimensional Bose gas.An analysis based on the use of full quantum mechanical probability distributions of matter wave interference contrast reveals that the system evolves toward a quasi-steady state.This state, which can be characterized by an effective temperature, is not the final thermal equilibrium state.We compare the evolution of the system to an integrable Tomonaga-Luttinger liquid model, and show that the system dephases to a prethermalized state rather than undergoing thermalization toward a final thermal equilibrium state.
Abstract. We detail the experimental observation of the non-equilibrium many-body phenomenon prethermalization. We study the dynamics of a rapidly and coherently split one-dimensional Bose gas. An analysis based on the use of full quantum mechanical probability distributions of matter wave interference contrast reveals that the system evolves towards a quasi-steady state. This state, which can be characterized by an effective temperature, is not the final thermal equilibrium state. We compare the evolution of the system to an integrable Tomonaga-Luttinger liquid model, and show that the system dephases to a prethermalized state rather than undergoing thermalization towards a final thermal equilibrium state.
Quantum noise correlations have been employed in several areas in physics including condensed matter, quantum optics and ultracold atom to reveal non-classical states of the systems. So far, such analysis mostly focused on systems in equilibrium. In this paper, we show that quantum noise is also a useful tool to characterize and study the non-equilibrium dynamics of one dimensional system. We consider the Ramsey sequence of one dimensional, two-component bosons, and obtain simple, analytical expressions of time evolutions of the full distribution functions for this strongly-correlated, many-body system. The analysis can also be directly applied to the evolution of interference patterns between two one dimensional quasi-condensates created from a single condensate through splitting. Using the tools developed in this paper, we demonstrate that one dimensional dynamics in these systems exhibits the phenomenon known as "prethermalization", where the observables of non-equilibrium, long-time transient states become indistinguishable from those of thermal equilibrium states.
Quantum noise correlations have been employed in several areas of physics, including condensed matter, quantum optics and ultracold atoms, to reveal the non-classical states of the systems. To date, such analyses have mostly focused on systems in equilibrium. In this paper, we show that quantum noise is also a useful tool for characterizing and studying the non-equilibrium dynamics of a one-dimensional (1D) system. We consider the Ramsey sequence of 1D, two-component bosons, and obtain simple, analytical expressions for time evolutions of the full distribution functions for this strongly correlated, many-body system. The analysis can also be directly applied to the evolution of interference patterns between two 1D quasi-coindensates created from a single condensate through splitting. Using the tools developed in this paper, we demonstrate that 1D dynamics in these systems exhibits the phenomenon known as 'prethermalization', where the observables of non-equilibrium , long-time transient states become indistinguishable from those of thermal equilibrium states.
This paper explores the phenomenon of universal prethermalization in out-of-equilibrium interacting Bose-Fermi degenerate systems. Prethermalization, a transient non-equilibrium state characterized by a quasi-stationary distribution that is thermal with respect to a restricted set of effective conserved quantities, has emerged as a fundamental concept in the understanding of isolated quantum many-body systems far from equilibrium. We specifically focus on the unique interplay between bosonic and fermionic degrees of freedom, which introduces novel pathways for relaxation and distinct characteristics of prethermal plateaus. The universality of prethermal dynamics, implying independence from microscopic details and initial conditions within certain regimes, is investigated in the context of interspecies interactions, density imbalances, and dimensionality. We review the theoretical frameworks, including mean-field descriptions, effective Hamiltonians, and kinetic equations, alongside experimental observations in ultracold atomic gases that provide a fertile ground for studying such non-equilibrium phenomena. The emergence of universal scaling laws and the role of conservation laws in defining the prethermal state are discussed, paving the way for a deeper understanding of thermalization processes and the persistence of non-equilibrium states in complex quantum matter.
Non-equilibrium dynamics of isolated quantum many-body systems play an important role in many areas of physics. However, a general answer to the question of how these systems relax is still lacking. We experimentally study the dynamics of ultracold one-dimensional (1D) Bose gases. This reveals the existence of a quasi-steady prethermalized state which differs significantly from the thermal equilibrium of the system. Our results demonstrate that the dynamics of non-equilibrium quantum many-body systems is a far richer process than has been assumed in the past.
Prethermalization When a physical system is subjected to a rapid change of conditions (for example, a gas of atoms is allowed to occupy a volume twice the size of the original container), it quickly achieves a new temperature (thermalizes) through collisions. However, in some quantum systems many conserved variables inhibit thermalization; understanding the phases the systems go through in the slowing process is of great interest to cosmologists and physicists. Gring et al. (p. 1318 , published online 31 August) separate an ultracold one-dimensional gas of bosonic atoms into two nearly identical halves, and follow how local differences in phase between the halves evolve in time by examining their interference. Initially, the local phases are almost identical, but a rapid decoherence ensues, followed by a very slow further decay. The authors analyze the relative state reached after the initial fast decay and find that it can be described by an equilibrium function with an effective temperature several times less than the initial temperature. Because this cannot be the final state of the system, the authors term the initial process prethermalization.