Smirnov, K., Korneev, A., Minaeva, O., Divochiy, A., Tarkhov, M., Ryabchun, S., et al. (2007). Ultrathin NbN film superconducting single-photon detector array. In J. Phys.: Conf. Ser. (Vol. 61, pp. 1081–1085).
Abstract: We report on the fabrication process of the 2 × 2 superconducting single-photon detector (SSPD) array. The SSPD array is made from ultrathin NbN film and is operated at liquid helium temperatures. Each detector is a nanowire-based structure patterned by electron beam lithography process. The advances in fabrication technology allowed us to produce highly uniform strips and preserve superconducting properties of the unpatterned film. SSPD exhibit up to 30% quantum efficiency in near infrared and up to 1% at 5-μm wavelength. Due to 120 MHz counting rate and 18 ps jitter, the time-domain multiplexing read-out is proposed for large scale SSPD arrays. Single-pixel SSPD has already found a practical application in non-invasive testing of semiconductor very-large scale integrated circuits. The SSPD significantly outperformed traditional single-photon counting avalanche diodes.
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Verevkin, A. A., Ptitsina, N. G., Smirnov, K. V., Gol’tsman, G. N., Gershenzon, E. M., & Ingvesson, K. S. (1996). Direct measurements of energy relaxation times on an AlGaAs/GaAs heterointerface in the range 4.2–50 K. JETP Lett., 64(5), 404–409.
Abstract: The temperature dependence of the energy relaxation time τe (T) of a two-dimensional electron gas at an AlGaAs/GaAs heterointerface is measured under quasiequilibrium conditions in the region of the transition from scattering by acoustic phonons to scattering with the participation of optical phonons. The temperature interval of constant τe, where scattering by the deformation potential predominates, is determined. In the preceding, low-temperature region, where piezoacoustic and deformation-potential-induced scattering processes coexist, τ e decreases slowly with increasing temperature. Optical phonons start to participate in the scattering processes at T∼25 K (the characteristic phonon lifetime was equal to τLOτ4.5 ps). The energy losses calculated from the τe data in a model with an effective nonequilibrium electron temperature agree with the published data obtained under strong heating conditions.
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Korneev, A., Lipatov, A., Okunev, O., Chulkova, G., Smirnov, K., Gol’tsman, G., et al. (2003). GHz counting rate NbN single-photon detector for IR diagnostics of VLSI CMOS circuits. Microelectronic Engineering, 69(2-4), 274–278.
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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Smirnov, K. V., Ptitsina, N. G., Vakhtomin, Y. B., Verevkin, A. A., Gol’tsman, G. N., & Gershenzon, E. M. (2000). Energy relaxation of two-dimensional electrons in the quantum Hall effect regime. JETP Lett., 71(1), 31–34.
Abstract: The mm-wave spectroscopy with high temporal resolution is used to measure the energy relaxation times τe of 2D electrons in GaAs/AlGaAs heterostructures in magnetic fields B=0–4 T under quasi-equilibrium conditions at T=4.2 K. With increasing B, a considerable increase in τe from 0.9 to 25 ns is observed. For high B and low values of the filling factor ν, the energy relaxation rate τ −1e oscillates. The depth of these oscillations and the positions of maxima depend on the filling factor ν. For ν>5, the relaxation rate τ −1e is maximum when the Fermi level lies in the region of the localized states between the Landau levels. For lower values of ν, the relaxation rate is maximum at half-integer values of τ −1e when the Fermi level is coincident with the Landau level. The characteristic features of the dependence τ −1e (B) are explained by different contributions of the intralevel and interlevel electron-phonon transitions to the process of the energy relaxation of 2D electrons.
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Shangina, E. L., Smirnov, K. V., Morozov, D. V., Kovalyuk, V. V., Gol’tsman, G. N., Verevkin, A. A., et al. (2010). Concentration dependence of the intermediate frequency bandwidth of submillimeter heterodyne AlGaAs/GaAs nanostructures. Bull. Russ. Acad. Sci. Phys., 74(1), 100–102.
Abstract: The concentration dependence of the intermediate frequency bandwidth of heterodyne AlGaAs/GaAs detectors with 2D electron gas is measured using submillimeter spectroscopy with high time resolution at T= 4.2 K. The intermediate frequency bandwidth f3dBfalls from 245 to 145 MHz with increasing concentration of 2D electrons n s = (1.6-6.6) × 10[su11] cm-2. The dependence f3dB ≈ n s – 0.04±is observed in the studied concentration range; this dependence is determined by electron scattering by the deformation potential of acoustic phonons and piezoelectric scattering.
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