Constriction-limited detection efficiency of superconducting nanowire single-photon detectors
نویسندگان
چکیده
We investigate the source of large variations in the observed detection efficiencies of superconducting nanowire single-photon detectors between many nominally identical devices. Through both electrical and optical measurements, we infer that these variations arise from “constrictions:” highly localized regions of the nanowires where the effective cross-sectional area for superconducting current is reduced. These constrictions limit the bias current density to well below its critical value over the remainder of the wire, and thus prevent the detection efficiency from reaching the high values that occur in these devices only when they are biased near the critical current density.
منابع مشابه
Single-photon detectors based on ultranarrow superconducting nanowires.
We report efficient single-photon detection (η = 20% at 1550 nm wavelength) with ultranarrow (20 and 30 nm wide) superconducting nanowires, which were shown to be more robust to constrictions and more responsive to 1550 nm wavelength photons than standard superconducting nanowire single-photon detectors, based on 90 nm wide nanowires. We also improved our understanding of the physics of superco...
متن کاملWaveguide integrated low noise NbTiN nanowire single-photon detectors with milli-Hz dark count rate
Superconducting nanowire single-photon detectors are an ideal match for integrated quantum photonic circuits due to their high detection efficiency for telecom wavelength photons. Quantum optical technology also requires single-photon detection with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-photon detectors based on NbTiN thin f...
متن کاملModified detector tomography technique applied to a superconducting multiphoton nanodetector.
We present an experimental method to characterize multi-photon detectors with a small overall detection efficiency. We do this by separating the nonlinear action of the multiphoton detection event from linear losses in the detector. Such a characterization is a necessary step for quantum information protocols with single and multiphoton detectors and can provide quantitative information to unde...
متن کاملSuperconducting Nanowire Single photon detector (SNSPD) for Quantum Information
In the beginning of this century, a new type of detector, superconducting nanowire single photon detector (SNSPD or SSPD) joined the family of superconducting sensors and detectors. Soon, it has been turning to be one of the most important players in this family since it surpasses the semiconducting single photon detectors (APD: avalanche photodiode and PMT: photo multiplier tube) with many adv...
متن کاملNiobium Superconducting Nanowire Single-Photon Detectors
We investigate the performance of superconducting nanowire photon detectors fabricated from ultra-thin Nb. A direct comparison is made between these detectors and similar nanowire detectors fabricated from NbN. We find that Nb detectors are significantly more susceptible than NbN to thermal instability (latching) at high bias. We show that the devices can be stabilized by reducing the input res...
متن کامل