Critical velocity of a clean one-dimensional superconductor

Abstract

We revisit the problem of the critical velocity of a clean one-dimensional superconductor. {\changed At the level of mean-field theory}, we find that the zero-temperature value of the critical velocity--the uniform velocity of the superfluid condensate at which the superconducting state becomes unstable--is a factor of $\sqrt{2}$ smaller than the Landau critical velocity. This is in contrast to a prior finding, which held that the critical velocity is equal to the Landau critical velocity. The smaller value of the critical velocity, which our analysis yields, is the result of a pre-emptive Clogston-Chandrasekhar--like discontinuous phase transition, and is an analog of the threshold value of the uniform exchange-field of a superconductor, previously investigated by Sarma and by Maki and Tsuneto. We also consider the impact of nonzero temperature, study critical currents, and examine metastability and its limits in the temperature versus flow-velocity phase diagram. In addition, we comment on the effects of electron scattering by impurities.

Single column, double space, 24 pages, 10 figures

References in corpus (6)

• Evidence for a critical velocity in a Bose-Einstein condensed gas
• Reply to the Comment on 'Quantum Phase Slips and Transport in Ultra-Thin Superconducting Wires'
• Critical velocity for superfluid flow across the BEC-BCS crossover
• Geometrical destruction of the global phase coherence in ultrathin superconducting cylinders
• Emergence of $h/e$-period oscillations in the critical temperature of small superconducting rings threaded by magnetic flux
• Critical velocities in superfluids and the nucleation of vortices

Cited by in corpus (4)

• Asymmetric nanowire SQUID: linear CPR, stochastic switching, and symmetries
• Collective excitation and stability of flow-induced gapless Fermi superfluids
• Quantum interference in asymmetric superconducting nanowire loops
• Boosted one dimensional superfluids on a lattice