Tunneling Asymmetry in Spectroscopy of the Conventional Superconductor V_3Si
Abstract
Scanning tunneling spectroscopy (STS) of the conventional superconductor V_3Si reveals an unusual asymmetry about the Fermi energy, with the tunneling conductance higher for filled than for empty quasi-particle states. These results, not before observed in conventional superconductors, are reminiscent of the unexplained asymmetric spectra of high-TC materials. The measured asymmetry appears associated with superconductivity, disappearing as TC is approached from below. The samples, ~ 40 nm thin films of V_3Si grown by molecular beam epitaxy, were characterized by electron probe microanalysis and SQUID magnetometry to determine their stoichiometry and bulk transition temperatures respectively. STS measurements of this tunneling asymmetry as a function of temperature (from 2.3 K to 10 K), magnetic field (from 0 T to 10 T) and junction impedance (from 1 MΩ to 1 GΩ) will be presented and discussed.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2002
- Bibcode:
- 2002APS..MARB13010H