Superconductivity of niobium thin films in the BiOCl/Nb heterostructures

TL;DR

This study investigates how laser light affects the superconducting properties of 25 nm niobium films on BiOCl, revealing interface effects and carrier dynamics influenced by laser excitation.

Contribution

It provides new insights into the laser-induced modifications of superconductivity at the BiOCl/Nb interface and the role of the inverse proximity effect.

Findings

Laser excitation increases the normal to superconducting carrier ratio at the interface.

The resistivity behavior aligns with the McMillan model, indicating strong interface effects.

Photoconductivity of BiOCl correlates with changes in superconducting properties under laser light.

Abstract

In the current paper, electrical transport properties of 25 nm thick Nb films sputtered on the photosensitive semiconductor BiOCl were investigated in the temperature range 7.5 K $\leq T \leq$ 8.5 K. The influence of green (532 nm) and red (640 nm) laser excitations on resistive superconducting transitions of the niobium thin films on a silicon glass and BiOCl single crystal substrates were studied. The temperature dependences of the resistivity for Nb are in good agreement with the McMillan model which indicates the strong influence of the inverse proximity effect induced by the interface. The increased influence of the BiOCl/Nb interface under laser excitation corresponds to the raising the ratio of the density of normal to superconductivity carriers in the $T\rightarrow 0$ limit and this observation is in agreement with the photoconductivity study of BiOCl single crystals.