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Title: High quantum efficiency and low dark count rate in multi-layer superconducting nanowire single-photon detectors

In this paper, we theoretically show that a multi-layer superconducting nanowire single-photon detector (SNSPD) is capable of approaching characteristics of an ideal SNSPD in terms of the quantum efficiency, dark count, and band-width. A multi-layer structure improves the performance in two ways. First, the potential barrier for thermally activated vortex crossing, which is the major source of dark counts and the reduction of the critical current in SNSPDs is elevated. In a multi-layer SNSPD, a vortex is made of 2D-pancake vortices that form a stack. It will be shown that the stack of pancake vortices effectively experiences a larger potential barrier compared to a vortex in a single-layer SNSPD. This leads to an increase in the experimental critical current as well as significant decrease in the dark count rate. In consequence, an increase in the quantum efficiency for photons of the same energy or an increase in the sensitivity to photons of lower energy is achieved. Second, a multi-layer structure improves the efficiency of single-photon absorption by increasing the effective optical thickness without compromising the single-photon sensitivity.
Authors:
;  [1] ;  [2] ;  [1] ;  [2] ;  [3] ;  [2]
  1. Institute for Quantum Computing, Waterloo, Ontario N2L 3G1 (Canada)
  2. (Canada)
  3. (United States)
Publication Date:
OSTI Identifier:
22278112
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION; COMPARATIVE EVALUATIONS; COUNTING RATES; CRITICAL CURRENT; LAYERS; PERFORMANCE; PHOTONS; POTENTIALS; QUANTUM EFFICIENCY; QUANTUM WIRES; SENSITIVITY; SUPERCONDUCTING DEVICES; SUPERCONDUCTIVITY; VORTICES