Quantum sensing in highly non-linear superconducting nanowires enhanced superconducting nano-circuits

The project purpose is in extension of horizons of superconducting nanoelectronics as a building block of modern circuit quantum electrodynamics.

We will focus on resolution of fundamental limitations in single light quanta sensing systems as well as exploration of new quantum circuit capabilities offered by strongly nonlinear superconducting transport in highly ordered ultra-thin superconducting films of magnesium diboride (MgB2).

With it critical temperature of 36K in 5nm-thick films it offers to create a light-quantum sensing system which does not require sub- liquid helium cooling whereas showing high quantum efficiency at a photon flux exceeding 109 Hz.

More specifically, our goals are in: a) technological and theoretical exploration of our recent discovery of extremely fast photon detection in epitaxially-grown superconducting ultrathin-film of MgB2, engineering its properties by controlled defect implanting offered by energetic helium ion beams, aiming at reaching highly efficient single-photon sensitivity for IR photons in a wide temperature range from 4K to 20K; b) exploitation of the observed very high non-linearity in kinetic inductance in MgB2 nanowires in reaching Ginzburg-Landau limits of superconductivity in demonstrations of highly tunable high-Q resonant circuits; c) monolithic and hybrid integration of dissimilar superconducting platforms combined with technological advances in thin film growth.