Running condensate in moving superfluid

TL;DR

This paper explores the theoretical possibility of excitations condensing at non-zero momentum in moving superfluids, with implications for superfluid helium, ultracold gases, and superconductors, analyzing order parameters and critical velocities.

Contribution

It introduces a Ginzburg-Landau model for excitations condensation in moving superfluids, providing new insights into their order parameters and critical velocities.

Findings

Potential condensation of excitations with non-zero momentum in moving superfluids.

Calculation of order parameters and energy gains associated with the condensation.

Determination of critical velocities for the onset of excitations condensation.

Abstract

A possibility of the condensation of excitations with non-zero momentum in moving superfluid media is considered in terms of the Ginzburg-Landau model. The results might be applicable to the superfluid $^4$He, ultracold atomic Bose gases, various superconducting and neutral systems with pairing, like ultracold atomic Fermi gases and the neutron component in compact stars. The order parameters, the energy gain, and critical velocities are found.