Abstract : We study the effect of disorder on the propagation of collective excitations in a disordered Bose superfluid. We incorporate local density depletion induced by strong disorder at the meanfield level, and formulate the transport of the excitations in terms of a screened scattering problem. We show that the competition of disorder, screening, and density depletion induces a strongly non-monotonic energy dependence of the disorder parameter. In three dimensions, it results in a rich localization diagram with four different classes of mobility spectra, characterized by either no or up to three mobility edges. Implications on experiments with disordered ultracold atoms are discussed.
https://hal-iogs.archives-ouvertes.fr/hal-01143356
Contributor : Lih-King Lim <>
Submitted on : Wednesday, April 22, 2015 - 9:56:32 AM Last modification on : Thursday, November 12, 2020 - 10:12:08 AM Long-term archiving on: : Tuesday, April 18, 2017 - 10:49:44 PM
Samuel Lellouch, Lih-King Lim, Laurent Sanchez-Palencia. Propagation of collective pair excitations in disordered Bose superfluids. Physical Review A, American Physical Society, 2015, 92, pp.043611. ⟨hal-01143356⟩