High-resistivity niobium nitride films for unity-efficiency SMSPDs at telecom wavelengths and beyond

TL;DR

This paper demonstrates that high-resistivity niobium nitride films enable superconducting microstrip single-photon detectors to achieve high detection efficiency at telecom wavelengths, overcoming limitations of wider strips.

Contribution

It introduces the use of high-resistivity niobium nitride films to improve the efficiency of microstrip superconducting single-photon detectors at larger widths.

Findings

Achieved highly saturated detection efficiency with high-resistivity films.

Enabled operation at telecom wavelengths and beyond.

Showed potential for improved experimental device performance.

Abstract

The sensitive element of superconducting single-photon detectors made in the form of a microstrip promise to resolve significant limitations caused by their typical design. However, attention should be paid to the problem of deterioration of the detection efficiency of devices with an increase of the width of the superconducting strip from nano- to microscale. This article demonstrates a possibility of achieving highly saturated detection efficiency of superconducting microstrip single-photon detectors by using high-resistivity niobium nitride films. The approach opens the way for employing fundamentally improved experimental devices.