Afterpulsing and Instability in Superconducting Nanowire Avalanche Photodetectors

TL;DR

This study examines the reset time and stability of superconducting nanowire avalanche photodetectors, revealing trade-offs between speed, bias margin, and afterpulsing effects.

Contribution

It provides new insights into how device inductance affects reset time and stability, highlighting limitations and trade-offs in optimizing SNAP performance.

Findings

SNAPs can be faster than SNSPDs for the same area

Reducing inductance can cause instability and afterpulsing

A reset time below ~1 ns leads to afterpulsing

Abstract

We investigated the reset time of superconducting nanowire avalanche photodetectors (SNAPs) based on 30 nm wide nanowires. We studied the dependence of the reset time of SNAPs on the device inductance and discovered that SNAPs can provide a speed-up relative to SNSPDs with the same area, but with some limitations: (1) reducing the series inductance of SNAPs (necessary for the avalanche formation) could result in the detectors operating in an unstable regime; (2) a trade-off exists between maximizing the bias current margin and minimizing the reset time of SNAPs; and (3) reducing the reset time of SNAPs below ~ 1 ns resulted in afterpulsing.