Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5492297 | Physica C: Superconductivity and its Applications | 2017 | 6 Pages |
Abstract
A promising direction to improve the sensitivity of a SQUID is to increase its junction's normal resistance value, Rn, as the SQUID modulation voltage scales linearly with Rn. As a first step to develop highly sensitive single layer SQUID, submicron scale YBCO grain boundary step edge junctions and SQUIDs with large Rn were fabricated and studied. The step-edge junctions were reduced to submicron scale to increase their Rn values using focus ion beam, FIB and the measurement of transport properties were performed from 4.3 to 77â¯K. The FIB induced deposition layer proves to be effective to minimize the Ga ion contamination during the FIB milling process. The critical current-normal resistance value of submicron junction at 4.3â¯K was found to be 1-3â¯mV, comparable to the value of the same type of junction in micron scale. The submicron junction Rn value is in the range of 35-100â¯Î©, resulting a large SQUID modulation voltage in a wide temperature range. This performance promotes further investigation of cryogen-free, high field sensitivity SQUID applications at medium low temperature, e.g. at 40-60â¯K.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Simon K.H. Lam,