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Verevkin, A., Williams, C., Gol’tsman, G. N., Sobolewski, R., & Gilbert, G. (2001). Single-photon superconducting detectors for practical high-speed quantum cryptography. Optical Society of America.
Abstract: We have developed an ultrafast superconducting single-photon detector with negligible dark counting rate. The detector is based on an ultrathin, submicron-wide NbN meander-type stripe and can detect individual photons in the visible to near-infrared wavelength range at a rate of at least 10 Gb/s. The above counting rate allows us to implement the NbN device to unconditionally secret quantum key distRochester, New Yorkribution in a practical, high-speed system using real-time Vernam enciphering.
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Verevkin, A., Slysz, W., Pearlman, A., Zhang, J., Sobolewski, R., Okunev, O., et al. (2003). Real-time GHz-rate counting of infrared photons using nanostructured NbN superconducting detectors. In CLEO/QELS (CThM8). Optical Society of America.
Abstract: We demonstrate that our ultrathin, nanometer-width NbN superconducting single-photon detectors are capable of above 1-GHz-frequency, real-time counting of near-infrared photons. The measured system jitter of the detector is below 15 ps.
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Verevkin, A., Pearlman, A., Slysz, W., Zhang, J., Currie, M., Korneev, A., et al. (2004). Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications. J. Modern Opt., 51(9-10), 1447–1458.
Abstract: The paper reports progress on the design and development of niobium-nitride, superconducting single-photon detectors (SSPDs) for ultrafast counting of near-infrared photons for secure quantum communications. The SSPDs operate in the quantum detection mode, based on photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-width superconducting stripe. The devices are fabricated from 3.5 nm thick NbN films and kept at cryogenic (liquid helium) temperatures inside a cryostat. The detector experimental quantum efficiency in the photon-counting mode reaches above 20% in the visible radiation range and up to 10% at the 1.3–1.55 μn infrared range. The dark counts are below 0.01 per second. The measured real-time counting rate is above 2 GHz and is limited by readout electronics (the intrinsic response time is below 30 ps). The SSPD jitter is below 18 ps, and the best-measured value of the noise-equivalent power (NEP) is 2 × 10−18 W/Hz1/2. at 1.3 μm. In terms of photon-counting efficiency and speed, these NbN SSPDs significantly outperform semiconductor avalanche photodiodes and photomultipliers.
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Verevkin, A., Gershenzon, E. M., Gol'tsman, G. N., Ptitsina, N. G., Chulkova, G. M., Smirnov, K. S., et al. (2002). Direct measurements of energy relaxation times in two-dimensional structures under quasi-equilibrium conditions. In Mater. Sci. Forum (Vol. 384-3, pp. 107–116).
Abstract: A new microwave technique was successfully applied for direct studies of energy relaxation times in two-dimensional AlGaAs/GaAs structures under quasi-equilibrium conditions in the nanosecond and picosecond time scale. We report our results of energy relaxation time measurements in the temperature range 1.6-50 K, in quantum Hall effect regime in magnetic fields up to 4 T.
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Verevkin, A. I., Ptitsina, N. G., Chulkova, G. M., Gol'tsman, G. N., Gershenzon, E. M., & Yngvesson, K. S. (1995). Electron energy relaxation in a 2D channel in AlGaAs-GaAs heterostructures under quasiequilibrium conditions at low temperatures. JETP Lett., 61(7), 591–595.
Abstract: The energy relaxation time of 2D electrons, Te, has been measured under quasiequilibrium conditions in AlGaAs—GaAs heterojunctions over the temperature range T= 1.5—20 K. At T> 4 K, Te depends only weakly on the temperature, while at T< 4 K 7;'(T) there is a dependence fr; lNT. A linear dependence 7: 1 (T) in the Bloch—-Grfineisen temperature region (T< 5 K) is unambiguous evidence that a piezoacoustic mechanism of an electron—phonon interaction is predominant in the inelastic scattering of electrons. The values of T6 in this temperature range agree very accurately with theoretical results reported by Karpus [Sov. Phys. Semicond. 22 (1988)]. At higher temperatures, where scat—tering by deformation acoustic phonons becomes substantial, there is a significant discrepancy between the experimental and theoretical re-sults.
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