Observation of Quantum Equilibration in Dilute Bose Gases

Abstract

We investigate experimentally the dynamical relaxation of a non-integrable quantum many-body system to its equilibrium state. A Bose-Einstein condensate is loaded into the first excited band of an optical lattice and let to evolve up to a few hundreds of milliseconds. Signs of quantum equilibration are observed. There is a period of time, roughly 40 ms long, during which both the aspect ratio of the cloud and its momentum distribution remain constant. In particular, the momentum distribution has a flat top and is not a Gaussian thermal distribution. After this period, the cloud becomes classical as its momentum distribution becomes Gaussian.

6 pages, 4 figures

References in corpus (10)

• Foundation of Statistical Mechanics under experimentally realistic conditions
• Emergence of turbulence in an oscillating Bose-Einstein condensate
• Orbital superfluidity in the $P$-band of a bipartite optical square lattice
• Proof of the Ergodic Theorem and the H-Theorem in Quantum Mechanics
• Long-Time Behavior of Macroscopic Quantum Systems: Commentary Accompanying the English Translation of John von Neumann's 1929 Article on the Quantum Ergodic Theorem
• Non-equilibrium dynamics of bosonic atoms in optical lattices: Decoherence of many-body states due to spontaneous emission
• Heating dynamics of bosonic atoms in a noisy optical lattice
• Orbital optical lattices with bosons
• Entropy for Quantum Pure States and Its Dynamical Relaxation
• Stability of $p$-orbital Bose-Einstein condensates in optical checkerboard and square lattices

Cited by in corpus (5)

• Shortcut loading atoms into an optical lattice
• Optimized fringe removal algorithm for absorption images
• Extraction and identification of noise patterns for ultracold atoms in an optical lattice
• Study to improve the performance of interferometer with ultra-cold atoms
• Roles of energy eigenstates and eigenvalues in equilibration of isolated quantum systems