2005/11/30 by A. Kohen, Th. Proslier, Tristan Cren +6 · 2 citations
Materials Science · Physics and Astronomy · #Coherence length #Condensed matter physics #Iron-based superconductors research #Length scale #London penetration depth #Magnetic field #Optics #Penetration depth #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum tunnelling #Quasiparticle #Scanning tunneling microscope #Superconductivity #Superconductivity in MgB2 and Alloys #Superfluid helium-4 #Superfluidity #Type-II superconductor #Vortex #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.97.027001
4 pages, 5 figures
arxiv created 2005/11/30 · openalex publication_date 2006/07/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We address the question of probing the supercurrents in superconducting (SC) samples on a local scale by performing scanning tunneling spectroscopy (STS) experiments with a SC tip. In this configuration, we show that the tunneling conductance is highly sensitive to the Doppler shift term in the SC quasiparticle (QP) spectrum of the sample, thus allowing the local study of the superfluid velocity. Intrinsic screening currents, such as those surrounding the vortex cores in a type II SC in a magnetic field, are directly probed. With Nb tips, the STS mapping of the vortices, in single crystal 2H-NbSe(2), reveals both the vortex cores, on the scale of the SC coherence length xi, and the supercurrents, on the scale of the London penetration length lambda. A subtle interplay between the SC pair potential and the supercurrents at the vortex edge is observed. Our results open interesting prospects for the study of screening currents in any superconductor.