Physical mechanisms of timing jitter in photon detection by current carrying superconducting nanowires

TL;DR

This study investigates the physical origins of timing jitter in superconducting nanowire photon detectors, revealing deterministic and probabilistic regimes influenced by current, photon energy, and nanowire geometry.

Contribution

It identifies two distinct physical mechanisms underlying timing jitter, linking them to current, photon energy, and nanowire bend geometry, advancing understanding of detector performance.

Findings

Jitter decreases with current at high photon energies in the deterministic regime.

Jitter increases at low photon energies and becomes independent of current.

In the probabilistic regime, jitter is governed by vortex crossings near bends.

Abstract

We studied timing jitter in the appearance of photon counts in meandering nanowires with different fractional amount of bends. Timing jitter, which is the probability density of the random time delay between photon absorption in current-carrying superconducting nanowire and appearance of the normal domain, reveals two different underlying physical scenarios. In the deterministic regime, which is realized at large currents and photon energies, jitter is controlled by position dependent detection threshold in straight parts of meanders and decreases with the current. At small photon energies, jitter increases and its current dependence disappears. In this probabilistic regime jitter is controlled by Poisson process in that magnetic vortices jump randomly across the wire in areas adjacent to the bends.