Zero sound in a single component fermion - Bose Einstein Condensate mixture

TL;DR

This paper investigates zero-sound modes in a cold atom mixture of fermions and a BEC, revealing complex collective behaviors, instabilities, and mode interactions relevant for understanding quantum many-body dynamics.

Contribution

It provides the first detailed analysis of zero-sound in a single-component fermion-BEC mixture, including instability criteria and mode structure.

Findings

Identification of a stable undamped zero-sound mode with avoided crossing

Discovery of a Landau-damped mode that terminates

Characterization of phase separation instability

Abstract

The resonant dynamics of mediated interactions supports zero-sound in a cold atom degenerate mixture of a single component fermion gas and a Bose-Einstein condensate (BEC). We characterize the onset of instability in the phase separation of an unstable mixture and we find a rich collective mode structure for stable mixtures with one undamped mode that exhibits an avoided crossing and a Landau-damped mode that terminates.