A scalable multi-photon coincidence detector based on superconducting nanowires

TL;DR

This paper introduces a scalable superconducting nanowire-based coincidence detector capable of resolving multi-photon events, significantly advancing multi-photon detection in large-scale quantum photonic circuits.

Contribution

It presents a novel two-terminal detector architecture that enables scalable, photon-number-resolving coincidence detection for large arrays of superconducting nanowire segments.

Findings

Demonstrated a 16-element detector resolving 136 single- and two-photon events.

Resolved up to four-photon coincidences in a 4-element device.

Showcased potential for integration into large-scale quantum photonic systems.

Abstract

Coincidence detection of single photons is crucial in numerous quantum technologies and usually requires multiple time-resolved single-photon detectors. However, the electronic readout becomes a major challenge when the measurement basis scales to large numbers of spatial modes. Here, we address this problem by introducing a two-terminal coincidence detector that enables scalable readout of an array of detector segments based on superconducting nanowire microstrip transmission line. Exploiting timing logic, we demonstrate a 16-element detector that resolves all 136 possible single-photon and two-photon coincidence events. We further explore the pulse shapes of the detector output and resolve up to four-photon coincidence events in a 4-element device, giving the detector photon-number-resolving capability. This new detector architecture and operating scheme will be particularly useful for multi-photon coincidence detection in large-scale photonic integrated circuits.