2005/07/13 by David Pekker, Alexey Bezryadin, David Hopkins +2 · 29 citations
Physics and Astronomy · #Coherence length #Condensed matter physics #Electrical engineering #Josephson effect #Magnetic field #Materials science #Mesoscopic physics #Nanotechnology #Nanowire #Penetration depth #Physics #Physics of Superconductivity and Magnetism #Proximity effect (electron beam lithography) #Quantum and electron transport phenomena #Quantum mechanics #Resistive touchscreen #Superconducting coherence length #Superconducting wire #Superconductivity #Superconductivity in MgB2 and Alloys #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.72.104517
published in Physical Review B 72(10) (American Physical Society) · 20 pages, 18 figures
arxiv created 2005/07/13 · openalex publication_date 2005/09/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A theory describing the operation of a superconducting nanowire quantum interference device (NQUID) is presented. The device consists of a pair of thin-film superconducting leads connected by a pair of topologically parallel ultranarrow superconducting wires. It exhibits intrinsic electrical resistance, due to thermally activated dissipative fluctuations of the superconducting order parameter. Attention is given to the dependence of this resistance on the strength of an externally applied magnetic field aligned perpendicular to the leads, for lead dimensions such that there is essentially complete and uniform penetration of the leads by the magnetic field. This regime, in which at least one of the lead dimensions---length or width---lies between the superconducting coherence and penetration lengths, is referred to as the mesoscopic regime. The magnetic field causes a pronounced oscillation of the device resistance, with a period not dominated by the Aharonov-Bohm effect through the area enclosed by the wires and the film edges but, rather, in terms of the geometry of the leads, in contrast to the well-known Little-Parks resistance of thin-walled superconducting cylinders. A detailed theory, encompassing this phenomenology quantitatively, is developed through extensions, to the setting of parallel superconducting wires, of the Ivanchenko-Zil'berman-Ambegaokar-Halperin theory of intrinsic resistive fluctuations in a current-biased Josephson junction and the Langer-Ambegaokar-McCumber-Halperin theory of intrinsic resistive fluctuations in a superconducting wire. In particular, it is demonstrated that via the resistance of the NQUID, the wires act as a probe of spatial variations in the superconducting order parameter along the perimeter of each lead: in essence, a superconducting phase gradiometer.