Ultimate Vortex Confinement Studied by Scanning Tunneling Spectroscopy
Abstract
We report a detailed scanning tunneling microscopy study of a superconductor in a strong vortex confinement regime. This is achieved in a thin nanoisland of Pb having a size d about 3 times the coherence length, and a thickness h such that h≪d≪λ, where λ is the London penetration depth. In this geometry the magnetic field evolution of local tunneling spectra reveals only two superconducting configurations to exist: zero and single vorticity. The normal state is reached at μ0Hc=0.46T, about 6 times the critical field of bulk Pb, with no higher order vorticity observed. Basing on our STS data, we discuss the role of local supercurrents in both configurations.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2009
- DOI:
- 10.1103/PhysRevLett.102.127005
- Bibcode:
- 2009PhRvL.102l7005C
- Keywords:
-
- 74.25.Sv;
- 74.25.Ha;
- 74.78.Na;
- Critical currents;
- Magnetic properties;
- Mesoscopic and nanoscale systems