Suppression of superconductivity in nanowires by bulk superconductors

TL;DR

This study investigates how bulk superconductors influence the superconductivity of zinc nanowires, revealing suppression effects that depend on wire size and electrode state, with potential implications for nanoscale superconducting devices.

Contribution

It demonstrates the suppression of superconductivity in zinc nanowires by bulk superconductors and how this effect varies with wire diameter and electrode state.

Findings

Superconductivity in 40 nm zinc nanowires is suppressed by bulk superconducting electrodes.

Switching to normal state electrodes restores nanowire superconductivity.

Suppression effect diminishes in wires with diameters ≥70 nm.

Abstract

Transport measurements were made on a system consisting of a zinc nanowire array sandwiched between two bulk superconducting electrodes (Sn or In). It was found that the superconductivity of Zn nanowires of 40 nm diameter is suppressed either completely or partially by the superconducting electrodes. When the electrodes are driven into their normal state by a magnetic field, the nanowires switch back to their superconducting state. This phenomenon is significantly weakened when one of the two superconducting electrodes is replaced by a normal metal. The phenomenon is not seen in wires with diameters equal to and thicker than 70 nm.