Gated Mode Superconducting Nanowire Single Photon Detectors

TL;DR

This paper introduces a gated mode operation for superconducting nanowire single photon detectors, achieving GHz count rates and reducing dark counts, significantly improving their speed and efficiency for quantum applications.

Contribution

The paper presents the first implementation of gated mode SNSPDs, enabling GHz count rates without sacrificing active area or quantum efficiency.

Findings

Achieved 625MHz count rate in GM-SNSPDs

Demonstrated operation at GHz range without efficiency loss

Reduced dark count rate compared to free-running mode

Abstract

Single Photon Detectors (SPD) are fundamental to quantum optics and quantum information. Superconducting Nanowire SPDs (SNSPD) [1] provide high performance in terms of quantum efficiency (QE), dark count rate (DCR) and timing jitter [2], but have limited maximum count rate (MCR) when operated as a free-running mode (FM) detector [3, 4]. However, high count rates are needed for many applications like quantum computing [5] and communication [6], and laser ranging [7]. Here we report the first operation of SNSPDs in a gated mode (GM) that exploits a single photon triggered latching phenomenon to detect photons. We demonstrate operation of a large active area single element GM-SNSPD at 625MHz, one order of magnitude faster than its FM counterpart. Contrary to FM-SNSPDs, the MCR in GM can be pushed to GHz range without a compromise on the active area or QE, while reducing the DCR.