Integrating Superconductive and Optical Circuits

TL;DR

This paper demonstrates the integration of superconductive circuits with optical waveguides on silicon wafers, showing optical control of superconducting junctions via light coupling and analyzing the effects on superconducting properties.

Contribution

It presents a novel fabrication process for integrating superconductive films and optical waveguides, enabling optical manipulation of superconducting devices on silicon wafers.

Findings

660 nm light affects superconducting tunnel junctions' I-V characteristics

Optical pumping influences the superconducting energy gap

Integration process is solid and non-invasive

Abstract

We have integrated on oxidized silicon wafers superconductive films and Josephson junctions along with sol-gel optical channel waveguides. The fabrication process is carried out in two steps that result to be solid and non-invasive. It is demonstrated that 660 nm light, coupled from an optical fibre into the channel sol-gel waveguide, can be directed toward superconducting tunnel junctions whose current-voltage characteristics are affected by the presence of the radiation. The dependence of the change in the superconducting energy gap under optical pumping is discussed in terms of a non-equilibrium superconductivity model.