Vortex assisted mechanism of photon counting in superconducting nanowire single photon detector revealed by external magnetic field

Abstract

We use external magnetic field to probe the detection mechanism of superconducting nanowire single photon detector. We argue that the hot belt model (which assumes partial suppression of the superconducting order parameter $\Delta$ across the whole width of the superconducting nanowire after absorption of the single photon) does not explain observed weak field dependence of the photon count rate (PCR) for photons with $\lambda$=450 nm and noticeable {\it decrease} of PCR (with increasing the magnetic field) in some range of the currents for photons with wavelengths $\lambda$ =450-1200 nm. Found experimental results for all studied wavelengths $\lambda =450-1550$ nm could be explained by the vortex hot spot model (which assumes partial suppression of $\Delta$ in the area with size smaller than the width of the nanowire) if one takes into account nucleation and entrance of the vortices to the photon induced hot spot and their pinning by the hot spot with relatively large size and strongly suppressed $\Delta$.

11 pages, 10 figures

References in corpus (6)

• Superconducting nanowire single-photon detectors: physics and applications
• Vortex-induced dissipation in narrow current-biased thin-film superconducting strips
• Intrinsic detection efficiency of superconducting single photon detector in the modified hot spot model
• Magnetic-field dependence of count rates in superconducting thin-film TaN single-photon detectors
• Current dependence of the 'red' boundary of superconducting single photon detectors in the modified hot spot model
• The effect of magnetic field on the intrinsic detection efficiency of superconducting single-photon detectors

Cited by in corpus (17)

• Theory of single photon detection by 'dirty' current-carrying superconducting strip based on the kinetic equation approach
• Fano fluctuations in superconducting nanowire single-photon detectors
• Characteristics of superconducting tungsten silicide WxSi1-x for single photon detection
• Intrinsic timing jitter and latency in superconducting single photon nanowire detectors
• Different single photon response of wide and narrow superconducting MoSi strips
• Determining the depairing current in superconducting nanowire single-photon detectors
• Supersonic dynamics of guided magnetic flux quanta
• Optically probing the detection mechanism in a molybdenum silicide superconducting nanowire single-photon detector
• Asymmetry in the effect of magnetic field on photon detection and dark counts in bended nanostrips
• Superconducting nanowires as high-rate photon detectors in strong magnetic fields
• Nanowire single-photon detectors made of atomic layer-deposited niobium nitride
• Experimental investigation of the detection mechanism in WSi nanowire superconducting single photon detectors
• Characterization of a photon-number resolving SNSPD using Poissonian and sub-Poissonian light
• Probabilistic vortex crossing criterion for superconducting nanowire single-photon detectors
• Defect controlled vortex generation in current-carrying narrow superconducting strips
• Multifunctional Superconducting Nanowire Quantum Sensors
• Timing jitter in photon detection by straight superconducting nanowires: Effect of magnetic field and photon flux