Three temperature regimes in superconducting photon detectors: Quantum, thermal and multiple phase-slips as generators of dark counts

Andrew Murphy, Alexander Semenov, Alexander Korneev, Yulia Korneeva, Gregory Gol'tsman, Alexey Bezryadin

Research output: Contribution to journalArticle

Abstract

We perform measurements of the switching current distributions of three w nm wide, 4 nm thick NbN superconducting strips which are used for single-photon detectors. These strips are much wider than the diameter of the vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We discover evidence of macroscopic quantum tunneling by observing the saturation of the standard deviation of the switching distributions at temperatures around 2K. We analyze our results using the Kurkijärvi-Garg model and find that the escape temperature also saturates at low temperatures, confirming that at sufficiently low temperatures, macroscopic quantum tunneling is possible in quasi-2D strips and can contribute to dark counts observed in single photon detectors. At the highest temperatures the system enters a multiple phase-slip regime. In this range single phase-slips are unable to produce dark counts and the fluctuations in the switching current are reduced.

Original languageEnglish (US)
Article number10174
JournalScientific reports
Volume5
DOIs
StatePublished - May 19 2015

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Three temperature regimes in superconducting photon detectors: Quantum, thermal and multiple phase-slips as generators of dark counts'. Together they form a unique fingerprint.

  • Cite this