We study the nonequilibrium dynamics of a coherently split one-dimensional Bose gas by measuring ... more We study the nonequilibrium dynamics of a coherently split one-dimensional Bose gas by measuring the full probability distribution functions of matter-wave interference. Observing the system on different length scales allows us to probe the dynamics of excitations on different energy scales, revealing two distinct length-scale-dependent regimes of relaxation. We measure the crossover length scale separating these two regimes and identify it with the prethermalized phase-correlation length of the system. Our approach enables a direct observation of the multimode dynamics characterizing one-dimensional quantum systems.
Imaging ultracold atomic gases close to surfaces is an important tool for the detailed analysis o... more Imaging ultracold atomic gases close to surfaces is an important tool for the detailed analysis of experiments carried out using atom chips. We describe the critical factors that need be considered, especially when the imaging beam is purposely reflected from the surface. In particular we present methods to measure the atom-surface distance, which is a prerequisite for magnetic field imaging and studies of atom surface-interactions.
ABSTRACT Understanding relaxation processes is an important unsolved problem in many areas of phy... more ABSTRACT Understanding relaxation processes is an important unsolved problem in many areas of physics. This fact is exacerbated by the scarcity of experimental tools for characterizing complex transient states. We employ measurements of full quantum mechanical probability distributions of matter-wave interference to study the relaxation dynamics of a coherently split one-dimensional Bose gas and obtain unprecedented information about the dynamical states of the system. Following an initial rapid evolution, the full distributions reveal the approach towards a thermal-like steady state which exhibits an effective temperature eight times lower than the initial equilibrium temperature of the system as well as a strong memory of the initial state prepared by the splitting process. We associate this thermal-like state with pre-thermalization.
We study the nonequilibrium dynamics of a coherently split one-dimensional Bose gas by measuring ... more We study the nonequilibrium dynamics of a coherently split one-dimensional Bose gas by measuring the full probability distribution functions of matter-wave interference. Observing the system on different length scales allows us to probe the dynamics of excitations on different energy scales, revealing two distinct length-scale-dependent regimes of relaxation. We measure the crossover length scale separating these two regimes and identify it with the prethermalized phase-correlation length of the system. Our approach enables a direct observation of the multimode dynamics characterizing one-dimensional quantum systems.
Imaging ultracold atomic gases close to surfaces is an important tool for the detailed analysis o... more Imaging ultracold atomic gases close to surfaces is an important tool for the detailed analysis of experiments carried out using atom chips. We describe the critical factors that need be considered, especially when the imaging beam is purposely reflected from the surface. In particular we present methods to measure the atom-surface distance, which is a prerequisite for magnetic field imaging and studies of atom surface-interactions.
ABSTRACT Understanding relaxation processes is an important unsolved problem in many areas of phy... more ABSTRACT Understanding relaxation processes is an important unsolved problem in many areas of physics. This fact is exacerbated by the scarcity of experimental tools for characterizing complex transient states. We employ measurements of full quantum mechanical probability distributions of matter-wave interference to study the relaxation dynamics of a coherently split one-dimensional Bose gas and obtain unprecedented information about the dynamical states of the system. Following an initial rapid evolution, the full distributions reveal the approach towards a thermal-like steady state which exhibits an effective temperature eight times lower than the initial equilibrium temperature of the system as well as a strong memory of the initial state prepared by the splitting process. We associate this thermal-like state with pre-thermalization.
Uploads
Papers by David A. Smith