Ultimate Vortex Confinement Studied by Scanning Tunneling Spectroscopy

Tristan Cren (1) , Denis Fokin (1) , François Debontridder (1) , Vincent Dubost (1) , Dimitri Rodichev (1)

1 INSP - Institut des Nanosciences de Paris

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=0.46  T, 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.

Domaines: Supraconductivité [cond-mat.supr-con]

Tristan Cren, Denis Fokin, François Debontridder, Vincent Dubost, Dimitri Rodichev. Ultimate Vortex Confinement Studied by Scanning Tunneling Spectroscopy. Physical Review Letters, 2009, 102, pp.127005. ⟨10.1103/PhysRevLett.102.127005⟩. ⟨hal-00449718⟩