Soft X-Ray Single-Photon Detection With Superconducting Tantalum Nitride and Niobium Nanowires

TL;DR

This paper presents the development and comparison of ultrafast, dark count-free soft X-ray single-photon detectors made from tantalum nitride and niobium nanowires, highlighting performance improvements and energy resolution capabilities.

Contribution

It introduces TaN-based X-SNSPDs with enhanced efficiency and energy resolution, and compares their properties to Nb-based detectors, revealing trade-offs related to conduction path widths.

Findings

TaN X-SNSPDs show improved detection efficiency and pulse amplitudes.

Wide conduction paths enable energy-resolving capability.

Detection efficiency at low temperatures is limited by conduction path width.

Abstract

We have fabricated ultrafast dark count-free soft X-ray single-photon detectors (X-SNSPDs) from TaN with various conduction path widths, and we compare their properties with corresponding data from a Nb X-SNSPD. The TaN X-SNSPDs offer an improved detector performance regarding device detection efficiency, latching and pulse amplitudes. Wide conduction paths allow for a certain energy-resolving capability in contrast to narrow TaN conduction paths. However, wide paths also limit the detection efficiency at low temperatures, which can be explained within a hot-spot model.