Modeling electrothermal feedback of superconducting nanowire single photon detectors in SPICE

TL;DR

This paper presents a compact SPICE-based thermal model for superconducting nanowire single-photon detectors that accurately captures residual heating effects, enabling faster circuit design without sacrificing detail.

Contribution

A novel, computationally efficient thermal model for SNSPDs integrated into SPICE, matching complex simulations and aiding rapid circuit development.

Findings

Model accurately replicates finite-element simulations.

Model captures complex residual heating effects.

Enables fast and intuitive circuit design.

Abstract

Superconducting nanowire single-photon detectors (SNSPDs) exhibit complex switching behaviors due to electrothermal feedback during the detection process. Modeling and understanding these behaviors is integral for designing superconducting devices; however, many models often prioritize accuracy over computational speed and intuitive integration for circuit designers. Here, we build upon a growing architecture of SPICE tools for superconducting nanowire devices by capturing complex residual heating effects in a compact thermal model of an SNSPD. We demonstrate that our model is comparable to more complicated thermal models of superconducting nanowire devices, including finite-element simulations, and is applicable for the fast development of SNSPD circuits.