Abstract
We consider a cloud of fermionic atoms in an optical lattice described by a Hubbard model with an additional linear potential. While homogeneous interacting systems mainly show damped Bloch oscillations and heating, a finite cloud behaves differently: It expands symmetrically such that gains of potential energy at the top are compensated by losses at the bottom. Interactions stabilize the necessary heat currents by inducing gradients of the inverse temperature , with at the bottom of the cloud. An analytic solution of hydrodynamic equations shows that the width of the cloud increases with for long times consistent with results from our Boltzmann simulations.
- Received 26 January 2011
DOI:https://doi.org/10.1103/PhysRevLett.106.250602
© 2011 American Physical Society