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Critical field for complete vortex expulsion from narrow superconducting strips



G Stan, S. Field, John M. Martinis


We have measured the maximum field for which vortices are completely expelled from a thin-film superconducting strip. Niobium strips of width W were field cooled and imaged with a scanning Hallprobe microscope. Below a critical field Bm 0=W2 all flux was expelled; above this field vortices were observed with a density increasing approximately linearly with field. The small value of the critical field, which is orders of magnitude less than in the bulk, implies that superconducting devices should be designed with narrow wires to eliminate the generation of noise from vortex motion.
Physical Review Letters


critical field, noise, superconducting devices, superconductivity, vortices


Stan, G. , Field, S. and Martinis, J. (2004), Critical field for complete vortex expulsion from narrow superconducting strips, Physical Review Letters, [online], (Accessed April 22, 2024)
Created March 4, 2004, Updated October 12, 2021