Probing the Hotspot Interaction Length in NbN Nanowire Superconducting Single-Photon Detectors

Abstract

We measure the maximal distance at which two absorbed photons can jointly trigger a detection event in NbN nanowire superconducting single photon detector (SSPD) microbridges by comparing the one-photon and two-photon efficiency of bridges of different overall lengths, from 0 to 400 nm. We find a length of $23\pm 2$ nm. This value is in good agreement with to size of the quasiparticle cloud at the time of the detection event.

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Cited by in corpus (2)

• Photonic quantum information processing: a concise review
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