Critical velocity of a clean one-dimensional superconductor

Article

关键词: CRITICAL FIELD;    ULTRATHIN;   

DOI  :  10.1103/PhysRevB.80.134507

来源: SCIE

【 摘 要 】

We revisit the problem of critical velocity of a clean one-dimensional superconductor. 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 root 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-type discontinuous phase transition, and is an analog of the threshold value of the uniform exchange field of a superconductor previously investigated by Sarma [J. Phys. Chem. Solids 24, 1029 (1963)] and by Maki and Tsuneto [Prog. Theor. Phys. 31, 945 (1964)]. 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.

【 授权许可】

Free