Superconductivity in single crystalline Pb nanowires contacted by normal metal electrodes

TL;DR

This study investigates the superconducting transport properties of single crystalline Pb nanowires with normal metal contacts, revealing resistance steps due to phase slip centers influenced by electrodes.

Contribution

It provides new insights into phase slip phenomena in Pb nanowires with normal metal electrodes, highlighting the role of contacts in superconducting behavior.

Findings

Resistance steps observed in R-T and R-H measurements.

Sharp steps in R-I scans indicating phase slip centers.

Electrode presence enhances phase slip effects.

Abstract

The transport properties of superconducting single crystal Pb nanowires of 55 nm and 70 nm diameter are studied by standard four electrodes method. Resistance-temperature (R-T) scans and magneto-resistance (R-H) measurements show a series of resistance steps with increasing temperature and magnetic field as the wires are brought toward the normal state. The resistance-current (R-I) scans at different temperature and magnetic field show that the increase in R with I is punctuated with sharp steps at specific current values. We interpret these steps as consequence of phase slip centers (PSCs) in the superconducting wires enhanced by the presence of the normal Pt electrodes.