Phase slip centers in long superconducting aluminum microbridges

• Published in: Journal of low temperature physics Vol. 65; no. 1-2; pp. 113 - 132
• Main Authors: LIENGME, O, BARATOFF, A, MARTINOLI, P
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.10.1986
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Metals, alloys and compounds (a15, 001c15, laves phases, chevrel phases, borocarbides, etc.); Metals, semimetals and alloys; Physics; Properties of type I and type II superconductors; Specific materials; Superconducting materials (excluding high-tc compounds); Superconductivity; Very low temperature; Electrical conductivity; Voltage current curve; Superconductivity
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/BF00685403

Phase slip center (PSC) measurements in long superconducting Al microbridges are reported. The usual divergence of the effective size 2 Lambda of a PSC, as indicated by its differential resistance, occurs only at temperatures extremely close to the critical temperature Tc. At lower temperatures Lambda is observed to be essentially constant; this is attributed to the onset of intermediate regions separating the core from the usual diverging regions of exponential electric field penetration (wings). In the low-temperature regime the equivalent decay time Lambda exp 2 /D is found to be much larger (50 ns) than the inelastic scattering time obtained from homogeneous charge imbalance experiments (12 ns). In contrast, an analysis of the divergence gives the same order of magnitude (7 ns). Furthermore, the onset of the intermediate regions is correlated with departure from local equilibrium close to the core. The effect of pair breaking on the local equilibrium condition is also discussed and compared with results from different experiments. Special emphasis is given to the interpretation of data from inhomogeneous samples where a spatially localized pair-breaking contribution is expected. Detailed analysis of the inhomogeneity itself provides complementary information and additional physical insight. 33 ref.--AA(UK/US).