Relaxation dynamics of an isolated large-spin Fermi gas far from equilibrium

Abstract

A fundamental question in many-body physics is how closed quantum systems reach equilibrium. We address this question experimentally and theoretically in an ultracold large-spin Fermi gas where we find a complex interplay between internal and motional degrees of freedom. The fermions are initially prepared far from equilibrium with only a few spin states occupied. The subsequent dynamics leading to redistribution among all spin states is observed experimentally and simulated theoretically using a kinetic Boltzmann equation with full spin coherence. The latter is derived microscopically and provides good agreement with experimental data without any free parameters. We identify several collisional processes, which occur on different time scales. By varying density and magnetic field, we control the relaxation dynamics and are able to continuously tune the character of a subset of spin states from an open to a closed system.

18 pages, 9 figures

References in corpus (11)

• Thermalization and its mechanism for generic isolated quantum systems
• Bose-Einstein condensation of chromium
• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Spontaneous symmetry breaking in a quenched ferromagnetic spinor Bose condensate
• Non-equilibrium coherence dynamics in one-dimensional Bose gases
• Itinerant Ferromagnetism in a Fermi Gas of Ultracold Atoms
• Observation of Anomalous Spin Segregation in a Trapped Fermi Gas
• Coherent multi-flavour spin dynamics in a fermionic quantum gas
• Multi-resonant spinor dynamics in a Bose-Einstein condensate
• Giant spin oscillations in an ultracold Fermi sea
• Dynamics of F=1 87Rb condensates at finite temperatures

Cited by in corpus (9)

• Coherent heteronuclear spin dynamics in an ultracold spin-1 mixture
• Competition between Bose Einstein Condensation and spin dynamics
• Coherent spin mixing dynamics in thermal ${}^{87}$Rb spin-1 and spin-2 gases
• Investigation of Feshbach Resonances in ultra-cold 40 K spin mixtures
• Manipulation of heteronuclear spin dynamics with microwave and vector light shift
• Spin diffusion in ultracold spin-orbit coupled ${}^{40}$K gas
• Formation of localized magnetic states in a large-spin Fermi system
• Correlations generated from high-temperature states: nonequilibrium dynamics in the Fermi-Hubbard model
• Magnetisms of spinor alkali and alkaline-earth atoms in optical lattices