Ex situ elaborated proximity mesoscopic structures for ultrahigh vacuum scanning tunneling spectroscopy

V. S. Stolyarov (1) , Ten Cren (1) , François Debontridder (1) , Christophe Brun (1) , I. S. Veshchunov , O. V. Skryabina , A. Yu. Rusanov , D. Roditchev (1)

1 INSP - Institut des Nanosciences de Paris

We apply ultrahigh vacuum Scanning Tunneling Spectroscopy (STS) at ultra-low temperature to study proximity phenomena in metallic Cu in contact with superconducting Nb. In order to solve the problem of Cu-surface contamination, Cu(50 nm)/Nb(100 nm) structures are grown by respecting the inverted order of layers on SiO2/Si substrate. Once transferred into vacuum, the samples are cleaved at the structure-substrate interface. As a result, a contamination-free Cu-surface is exposed in vacuum. It enables high-resolution STS of superconducting correlations induced by proximity from the underlying superconducting Nb layer. By applying magnetic field, we generate unusual proximity-induced superconducting vortices and map them with a high spatial and energy resolution. The suggested method opens a way to access local electronic properties of complex electronic mesoscopic devices by performing ex situ STS under ultrahigh vacuum. (C) 2014 AIP Publishing LLC.

Domaines: Matière Condensée [cond-mat]

V. S. Stolyarov, Ten Cren, François Debontridder, Christophe Brun, I. S. Veshchunov, et al.. Ex situ elaborated proximity mesoscopic structures for ultrahigh vacuum scanning tunneling spectroscopy. Applied Physics Letters, 2014, 104 (17), pp.172604. ⟨10.1063/1.4874647⟩. ⟨hal-01233575⟩