Flux noise in ion-implanted nanoSQUIDs

Abstract

Focused ion beam (FIB) technology has been used to fabricate miniature Nb DC SQUIDs which incorporate resistively-shunted microbridge junctions and a central loop with a hole diameter ranging from 1058 nm to 50 nm. The smallest device, with a 50 nm hole diameter, has a white flux noise level of 2.6 microphy_{0}/Hz^{0.5} at 10^{4} Hz. The scaling of the flux noise properties and focusing effect of the SQUID with the hole size were examined. The observed low-frequency flux noise of different devices were compared with the contribution due to the spin fluctuation of defects during FIB processing and the thermally activated flux hopping in the SQUID washer.

16 pages, 6 figures, 1 table

References in corpus (4)

• Model for l/f Flux Noise in SQUIDs and Qubits
• Josephson junctions and superconducting quantum interference devices made by local oxidation of niobium ultrathin films
• Direct measurement of penetration length in ultra-thin and/or mesoscopic superconducting structures
• Microscopic Analysis of Low-Frequency Flux Noise in YBa${}_2$Cu${}_3$O${}_7$ Direct Current Superconducting Quantum Interference Devices

Cited by in corpus (2)

• Nano Superconducting Quantum Interference device: a powerful tool for nanoscale investigations
• Superconducting transition in Nb nanowires fabricated using focused ion beam