Abstract
We study the propagation of sound in a homogeneous dipolar gas at zero temperature, which is known as zero sound. We find that undamped zero sound propagation is possible only in a range of solid angles around the direction of polarization of the dipoles. Above a critical dipole moment, we find an unstable mode, by which the gas collapses locally perpendicular to the dipoles’ direction.
- Received 22 November 2009
DOI:https://doi.org/10.1103/PhysRevA.81.033601
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