Strongly inhibited transport of a 1D Bose gas in a lattice

TL;DR

This study observes strong damping of dipole oscillations in a 1D Bose gas within an optical lattice, revealing nearly immobile behavior at higher lattice depths without quasimomentum broadening, possibly due to quantum fluctuations.

Contribution

It provides experimental evidence of quantum fluctuation-induced damping in 1D Bose gases in optical lattices, highlighting behavior at shallow to deep lattice potentials.

Findings

Damped dipole oscillations increase with lattice depth

No quasimomentum broadening observed after damping

Gas becomes nearly immobile at high lattice depths

Abstract

We report the observation of strongly damped dipole oscillations of a quantum degenerate 1D atomic Bose gas in a combined harmonic and optical lattice potential. Damping is significant for very shallow axial lattices (0.25 photon recoil energies), and increases dramatically with increasing lattice depth, such that the gas becomes nearly immobile for times an order of magnitude longer than the single-particle tunneling time. Surprisingly, we see no broadening of the atomic quasimomentum distribution after damped motion. Recent theoretical work suggests that quantum fluctuations can strongly damp dipole oscillations of 1D atomic Bose gas, providing a possible explanation for our observations.