Nonlocal conductance of small superconducting loops in the paraconductive regime

✍ Scribed by N.E. Israeloff; F. Yu; A.M. Goldman; R. Bojko

• Book ID: 103939992
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 394 KB
• Volume: 203
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)90096-5

✦ Synopsis

Both quasiparticles and superconducting fluctuations contribute to the conductance of superconductors in the paraconductive regime slightly above the transition temperature. The fluctuation contribution consists of the Maki-Thompson correction, which results from the scattering of electrons by a superconducting fluctuation, and the Aslamazov-Larkin contribution which describes the conductivity of a fluctuating electron pair. The latter is nonlocal over a length scale set by the fluctuation correlation length, ~(T). The observation of this nonlocality involves a multiterminal measurement of voltages in the paraconductive regime of a square superconducting loop of characteristic size, L ~ ~(T). The ratio of the voltages measured by two different sets of probes attached to the loop at different positions is found to oscillate as a function of the flux threading the loop. This effect is distinct from phenomena associated with the coherent transport of electrons in mesoscopic structures of a size smaller than the dephasing length, L~.