Position-Sensitive Response of Single-Pixel Large-Area SNSPDs

ORAL

Abstract

Superconducting nanowire single photon detectors (SNSPDs) are typically employed as single-pixel small-area detectors. Demand for large-area detectors is building for a variety of applications including microscopy and free-space quantum communication. Using large-area SNSPDs, we examine the leading edge of the readout pulse as a function of incident spot size, bias current, and mean photon number per pulse. We show a bimodal distribution of rise times that is correlated with spot size for small photon number. In the limit of low bias current, the set of dark-count readout pulses are most similar to the bright-count pulses at large spot size and small photon number. These observations are consistent with a model of traveling microwave modes excited by single photons incident at different positions along the length of the nanowire.

*This research was sponsored by the U. S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Student (BEL) and postdoctoral (CEM) research support were provided by the Intelligence Community Postdoctoral Research Fellowship Program at the Oak Ridge National Laboratory, administered by Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and the Office of the Director of National Intelligence and by the DOE Science Undergraduate Laboratory Internships (SULI) program. SNSPD measurements with pulsed laser sources were conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. The authors thank Matthew A. Feldman for support with microwave electronics.

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Authors

  • Brian Lerner

    • Oak Ridge National Lab