2004 |
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Verevkin A, Zhang J, Pearlman A, Slysz W, Sobolewski R, Korneev A, et al. Ultimate sensitivity of superconducting single-photon detectors in the visible to infrared range.; 2004.
Abstract: We present our quantum efficiency (QE) and noise equivalent power (NEP) measurements of the meandertype ultrathin NbN superconducting single-photon detector in the visible to infrared radiation range. The nanostructured devices with 3.5-nm film thickness demonstrate QE up to~ 10% at 1.3–1.55 µm wavelength, and up to 20% in the entire visible range. The detectors are sensitive to infrared radiation with the wavelengths down to~ 10 µm. NEP of about 2× 10-18 W/Hz1/2 was obtained at 1.3 µm wavelength. Such high sensitivity together with GHz-range counting speed, make NbN photon counters very promising for efficient, ultrafast quantum communications and another applications. We discuss the origin of dark counts in our devices and their ultimate sensitivity in terms of the resistive fluctuations in our superconducting nanostructured devices.
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2003 |
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Gol’tsman GN, Smirnov K, Kouminov P, Voronov B, Kaurova N, Drakinsky V, et al. Fabrication of nanostructured superconducting single-photon detectors. IEEE Trans Appl Supercond. 2003;13(2):192–5.
Abstract: Fabrication of NbN superconducting single-photon detectors, based on the hotspot effect is presented. The hotspot formation arises in an ultrathin and submicrometer-width superconductor stripe and, together with the supercurrent redistribution, leads to the resistive detector response upon absorption of a photon. The detector has a meander structure to maximally increase its active area and reach the highest detection efficiency. Main processing steps, leading to efficient devices, sensitive in 0.4-5 /spl mu/m wavelength range, are presented. The impact of various processing steps on the performance and operational parameters of our detectors is discussed.
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Korneev A, Lipatov A, Okunev O, Chulkova G, Smirnov K, Gol’tsman G, et al. GHz counting rate NbN single-photon detector for IR diagnostics of VLSI CMOS circuits. Microelectronic Engineering. 2003;69(2-4):274–8.
Abstract: We present a new, simple to manufacture superconducting single-photon detector operational in the range from ultraviolet to mid-infrared radiation wavelengths. The detector combines GHz counting rate, high quantum efficiency and very low level of dark (false) counts. At 1.3–1.5 μm wavelength range our detector exhibits a quantum efficiency of 5–10%. The detector photoresponse voltage pulse duration was measured to be about 150 ps with jitter of 35 ps and both of them were limited mostly by our measurement equipment. In terms of quantum efficiency, dark counts level, speed of operation the detector surpasses all semiconductor counterparts and was successfully applied for CMOS integrated circuits diagnostics.
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Semenov A, Engel A, Il'in K, Gol'tsman G, Siegel M, Hübers H-W. Ultimate performance of a superconducting quantum detector. Eur Phys J Appl Phys. 2003;21(3):171–8.
Abstract: We analyze the ultimate performance of a superconducting quantum detector in order to meet requirements for applications in near-infrared astronomy and X-ray spectroscopy. The detector exploits a combined detection mechanism, in which avalanche quasiparticle multiplication and the supercurrent jointly produce a voltage response to a single absorbed photon via successive formation of a photon-induced and a current-induced normal hotspot in a narrow superconducting strip. The response time of the detector should increase with the photon energy providing energy resolution. Depending on the superconducting material and operation conditions, the cut-off wavelength for the single-photon detection regime varies from infrared waves to visible light. We simulated the performance of the background-limited infrared direct detector and X-ray photon counter utilizing the above mechanism. Low dark count rate and intrinsic low-frequency cut-off allow for realizing a background limited noise equivalent power of 10−20 W Hz−1/2 for a far-infrared direct detector exposed to 4-K background radiation. At low temperatures, the intrinsic response time of the counter is rather determined by diffusion of nonequilibrium electrons than by the rate of energy transfer to phonons. Therefore, thermal fluctuations do not hamper energy resolution of the X-ray photon counter that should be better than 10−3 for 6-keV photons. Comparison of new data obtained with a Nb based detector and previously reported results on NbN quantum detectors support our estimates of ultimate detector performance.
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Sobolewski R, Verevkin A, Gol'tsman GN, Lipatov A, Wilsher K. Ultrafast superconducting single-photon optical detectors and their applications. IEEE Trans. Appl. Supercond.. 2003;13(2):1151–7.
Abstract: We present a new class of ultrafast single-photon detectors for counting both visible and infrared photons. The detection mechanism is based on photon-induced hotspot formation, which forces the supercurrent redistribution and leads to the appearance of a transient resistive barrier across an ultrathin, submicrometer-width, superconducting stripe. The devices were fabricated from 3.5-nm- and 10-nm-thick NbN films, patterned into <200-nm-wide stripes in the 4 /spl times/ 4-/spl mu/m/sup 2/ or 10 /spl times/ 10-/spl mu/m/sup 2/ meander-type geometry, and operated at 4.2 K, well below the NbN critical temperature (T/sub c/=10-11 K). Continuous-wave and pulsed-laser optical sources in the 400-nm-to 3500-nm-wavelength range were used to determine the detector performance in the photon-counting mode. Experimental quantum efficiency was found to exponentially depend on the photon wavelength, and for our best, 3.5-nm-thick, 100-/spl mu/m/sup 2/-area devices varied from >10% for 405-nm radiation to 3.5% for 1550-nm photons. The detector response time and jitter were /spl sim/100 ps and 35 ps, respectively, and were acquisition system limited. The dark counts were below 0.01 per second at optimal biasing. In terms of the counting rate, jitter, and dark counts, the NbN single-photon detectors significantly outperform their semiconductor counterparts. Already-identified applications for our devices range from noncontact testing of semiconductor CMOS VLSI circuits to free-space quantum cryptography and communications.
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Sobolewski R, Zhang J, Slysz W, Pearlman A, Verevkin A, Lipatov A, et al. Ultrafast superconducting single-photon optical detectors. In: Spigulis J, Teteris J, Ozolinsh M, Lusis A, editors. Proc. SPIE. Vol 5123. SPIE; 2003. p. 1–11.
Abstract: We present a new class of single-photon devices for counting of both visible and infrared photons. Our superconducting single-photon detectors (SSPDs) are characterized by the intrinsic quantum efficiency (QE) reaching up to 100%, above 10 GHz counting rate, and negligible dark counts. The detection mechanism is based on the photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-wide superconducting stripe. The devices are fabricated from 3.5-nm-thick NbN films and operate at 4.2 K, well below the NbN superconducting transition temperature. Various continuous and pulsed laser sources in the wavelength range from 0.4 μm up to >3 μm were implemented in our experiments, enabling us to determine the detector QE in the photon-counting mode, response time, and jitter. For our best 3.5-nm-thick, 10×10 μm2-area devices, QE was found to reach almost 100% for any wavelength shorter than about 800 nm. For longer-wavelength (infrared) radiation, QE decreased exponentially with the photon wavelength increase. Time-resolved measurements of our SSPDs showed that the system-limited detector response pulse width was below 150 ps. The system jitter was measured to be 35 ps. In terms of the counting rate, jitter, and dark counts, the NbN SSPDs significantly outperform their semiconductor counterparts. Already identifeid and implemented applications of our devices range from noninvasive testing of semiconductor VLSI circuits to free-space quantum communications and quantum cryptography.
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Verevkin AA, Pearlman A, Slysz W, Zhang J, Sobolewski R, Chulkova G, et al. Ultrafast superconducting single-photon detectors for infrared wavelength quantum communications. In: Donkor E, Pirich AR, Brandt HE, editors. Proc. SPIE. Vol 5105. SPIE; 2003. p. 160–70.
Abstract: We have developed a new class of superconducting single-photon detectors (SSPDs) for ultrafast counting of infrared (IR) photons for secure quantum communications. The devices are operated on the quantum detection mechanism, based on the photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-wide superconducting stripe. The detectors are fabricated from 3.5-nm-thick NbN films and they operate at 4.2 K inside a closed-cycle refrigerator or liquid helium cryostat. Various continuous and pulsed laser sources have been used in our experiments, enabling us to determine the detector experimental quantum efficiency (QE) in the photon-counting mode, response time, time jitter, and dark counts. Our 3.5-nm-thick SSPDs reached QE above 15% for visible light photons and 5% at 1.3 – 1.5 μm infrared range. The measured real-time counting rate was above 2 GHz and was limited by the read-out electronics (intrinsic response time is <30 ps). The measured jitter was <18 ps, and the dark counting rate was <0.01 per second. The measured noise equivalent power (NEP) is 2 x 10-18 W/Hz1/2 at λ = 1.3 μm. In near-infrared range, in terms of the counting rate, jitter, dark counts, and overall sensitivity, the NbN SSPDs significantly outperform their semiconductor counterparts. An ultrafast quantum cryptography communication technology based on SSPDs is proposed and discussed.
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Zhang J, Boiadjieva N, Chulkova G, Deslandes H, Gol'tsman GN, Korneev A, et al. Noninvasive CMOS circuit testing with NbN superconducting single-photon detectors. Electron Lett. 2003;39(14):1086–8.
Abstract: The 3.5 nm thick-film, meander-structured NbN superconducting single-photon detectors have been implemented in the CMOS circuit-testing system based on the detection of near-infrared photon emission from switching transistors and have significantly improved the performance of the system. Photon emissions from both p- and n-MOS transistors have been observed.
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Zhang J, Pearlman A, Slysz W, Verevkin A, Sobolewski R, Wilsher K, et al. A superconducting single-photon detector for CMOS IC probing. In: Proc. 16-th LEOS. Vol 2.; 2003. p. 602–3.
Abstract: In this paper, a novel, time-resolved, NbN-based, superconducting single-photon detector (SSPD) has been developed for probing CMOS integrated circuits (ICs) using photon emission timing analysis (PETA).
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Zhang J, Słysz W, Pearlman A, Verevkin A, Sobolewski R, Okunev O, et al. Time delay of resistive-state formation in superconducting stripes excited by single optical photons. Phys Rev B. 2003;67(13):132508 (1 to 4).
Abstract: We have observed a 65(±5)-ps time delay in the onset of a resistive-state formation in 10-nm-thick, 130-nm-wide NbN superconducting stripes exposed to single photons. The delay in the photoresponse decreased to zero when the stripe was irradiated by multi-photon (classical) optical pulses. Our NbN structures were kept at 4.2 K, well below the material’s critical temperature, and were illuminated by 100-fs-wide optical pulses. The time-delay phenomenon has been explained within the framework of a model based on photon-induced generation of a hotspot in the superconducting stripe and subsequent, supercurrent-assisted, resistive-state formation across the entire stripe cross section. The measured time delays in both the single-photon and two-photon detection regimes agree well with theoretical predictions of the resistive-state dynamics in one-dimensional superconducting stripes.
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