A superheated Bose-condensed gas

Abstract

Our understanding of various states of matter usually relies on the assumption of thermodynamic equilibrium. However, the transitions between different phases of matter can be strongly affected by non-equilibrium phenomena. Here we demonstrate and explain an example of non-equilibrium stalling of a continuous, second-order phase transition. We create a superheated atomic Bose gas, in which a Bose-Einstein condensate (BEC) persists above the equilibrium critical temperature, $T_c$, if its coupling to the surrounding thermal bath is reduced by tuning interatomic interactions. For vanishing interactions the BEC persists in the superheated regime for a minute. However, if strong interactions are suddenly turned on, it rapidly "boils" away. Our observations can be understood within a two-fluid picture, treating the condensed and thermal components of the gas as separate equilibrium systems with a tuneable inter-component coupling. We experimentally reconstruct a non-equilibrium phase diagram of our gas, and theoretically reproduce its main features.

4.2 pages, 4 figures + 4 pages, 3 figures of supplementary information

References in corpus (14)

• Relaxation and Pre-thermalization in an Isolated Quantum System
• Spontaneous symmetry breaking in a quenched ferromagnetic spinor Bose condensate
• Light-cone-like spreading of correlations in a quantum many-body system
• Non-equilibrium coherence dynamics in one-dimensional Bose gases
• Repulsively bound atom pairs in an optical lattice
• Observation of an Efimov spectrum in an atomic system
• 39-K Bose-Einstein condensate with tunable interactions
• Effects of Interactions on the Critical Temperature of a Trapped Bose Gas
• Long timescale dynamics of spin textures in a degenerate F=1 ${}^{87}$ Rb spinor Bose gas
• Preparation and spectroscopy of a metastable Mott insulator state with attractive interactions
• Can a Bose gas be saturated?
• Efficient Production of Large 39K Bose-Einstein Condensates
• Condensed Fraction of an Atomic Bose Gas Induced by Critical Correlations
• Condensation dynamics in a quantum-quenched Bose gas

Cited by in corpus (9)

• Local emergence of thermal correlations in an isolated quantum many-body system
• Ultracold atoms out of equilibrium
• Quantum Joule-Thomson Effect in a Saturated Homogeneous Bose Gas
• Microscopic theory of phase transitions in a critical region
• Microscopic theory of a phase transition in a critical region: Bose-Einstein condensation in an interacting gas
• Scaling at the OTOC Wavefront: free versus chaotic models
• Dissipative Distillation of Supercritical Quantum Gases
• Two-dimensional Bose-Einstein condensate under pressure
• Damping of Confined Excitations Modes of 1D Condensates in an Optical Lattice