Optical manipulation of single flux quanta.

I S Veshchunov,A G Godin,Ph Tamarat,B Lounis,S V Mironov,A I Buzdin,W Magrini,J.-B Trebbia

doi:10.1038/ncomms12801

Abstract

Magnetic field can penetrate into type II superconductors in the form of Abrikosov vortices, which are magnetic flux tubes surrounded by circulating supercurrents often trapped at defects referred to as pinning sites. Although the average properties of the vortex matter in superconductors can be tuned with magnetic fields, temperature or electric currents, handling of individual Abrikosov vortices remains challenging and has been demonstrated only with sophisticated scanning local probe microscopies. Here we introduce a far-field optical method based on local heating of the superconductor with a focused laser beam to realize a fast and precise manipulation of individual vortices, in the same way as with optical tweezers. This simple approach provides the perfect basis for sculpting the magnetic flux profile in superconducting devices like a vortex lens or a vortex cleaner, without resorting to static pinning or ratchet effects.

Highlights

Magnetic field can penetrate into type II superconductors in the form of Abrikosov vortices, which are magnetic flux tubes surrounded by circulating supercurrents often trapped at defects referred to as pinning sites
Experiments showed that the average properties of the vortex matter can be tuned with magnetic fields[1], temperature or electric currents[2]
We introduce a far-field optical method based on local heating of the superconductor with a focused laser beam to realize a fast and precise manipulation of individual Abrikosov vortices

Summary

Results

A 90 nm-thick niobium film was cooled below its critical temperature Tc 1⁄4 8.6 K under a weak external magnetic field Hext applied perpendicular to the film, to set the SC in the mixed state. Hext 1⁄4 0.024 Oe. The vortices are located at pinning sites that are randomly distributed in the SC sample. The vortices are located at pinning sites that are randomly distributed in the SC sample

K d 25

Discussion

Methods