|
|
Cherednichenko, S., Rönnung, F., Gol'tsman, G., Kollberg, E., & Winkler, D. (2000). YBa2Cu3O7−δ hot-electron bolometer mixer. Phys. C: Supercond., 341-348, 2653–2654.
Abstract: We present an investigation of hot-electron bolometric mixer based on YBa2Cu3O7−δ (YBCO) superconducting thin film. Mixer conversion loss, absorbed local oscillator power and intermediate frequency bandwidth was measured at the local oscillator frequency 600 GHz. The fabrication technique for nanoscale YBCO hot-electron bolometer (HEB) mixer integrated into planar antenna structure is described.
|
|
|
|
Semenov, A., Goltsman, G., & Korneev, A. (2001). Quantum detection by current carrying superconducting film. Phys. C: Supercond., 351(4), 349–356.
Abstract: We describe a novel quantum detection mechanism in the superconducting film carrying supercurrent. The mechanism incorporates growing normal domain and breaking of superconductivity by the bias current. A single photon absorbed in the film creates transient normal spot that causes redistribution of the current and, consequently, increase of the current density in superconducting areas. When the current density exceeds the critical value, the film switches into resistive state and generates the voltage pulse. Analysis shows that a submicron-wide film of conventional low temperature superconductor operated in liquid helium may detect single far-infrared photon. The amplitude and duration of the voltage pulse are in the millivolt and picosecond range, respectively. The quantitative model is presented that allows simulation of the detector utilizing this detection mechanism.
|
|
|
|
Semenov, A. D., Hübers, H. - W., Richter, H., Birk, M., Krocka, M., Mair, U., et al. (2002). 2.5 THz heterodyne receiver with NbN hot-electron-bolometer mixer. Phys. C: Supercond., 372-376, 448–453.
Abstract: We describe a 2.5 THz heterodyne receiver for applications in astronomy and atmospheric research. The receiver employs a superconducting NbN phonon-cooled hot-electron-bolometer mixer and an optically pumped far-infrared gas laser as local oscillator. 2200 K double sideband mixer noise temperature was measured at 2.5 THz across a 1 GHz intermediate frequency bandwidth centred at 1.5 GHz. The total conversion losses were 17 dB. The mixer response was linear at load temperatures smaller than 400 K. The receiver was tested in the laboratory environment by measuring the methanol line in emission. Observed pressure broadening confirms the true heterodyne detection regime of the mixer.
|
|
|
|
Gol'tsman, G. N., Kouminov, P., Goghidze, I., & Gershenzon, E. M. (1994). Nonequilibrium kinetic inductive response of YBaCuO thin films to low-power laser pulses. Phys. C: Supercond., 235-240, 1979–1980.
Abstract: Transient non-equilibrium kinetic inductive voltage response of YBaCuO thin films to 20 ps pulses of YAG:Nd laser radiation with 0.63 μm and 1.5 μm wavelength has been revealed. By increasing the sensitivity of 100 ps resolution time registration system and diminishing light intensity (fluence 0.1-1 μJ2/cm2) and transport current (density j≤105 A/cm2) we observed a perculiar bipolar signal form with nearly equal amplitudes of each sign. The integration of the kinetic inductive response over time gives the result which is qualitatively of the same form as the response in the resistive and normal states: nonequilibrium picosecond scale component followed by bolometric nanosecond. Nonequilibrium response is interpreted as suppression of order parameter by excess of quasiparticles followed by a change in resistance in the resistive state and kinetic inductance in superconductive state.
|
|
|
|
Gershenzon, E. M., Gol'tsman, G. N., Gogidze, I. G., Semenov, A. D., & Sergeev, A. V. (1991). Processes of electron-phonon interaction in thin YBaCuO films. Phys. C: Supercond., 185-189, 1371–1372.
Abstract: The ultrafast voltage response of YBaCuO films to laser radiation is studied and compared with previously investigated quasiparicles response to radiation of submillimeter wavelength range. Voltage shift under the visible light radiation has two components. Picosecond response realized as suppression superconductivity by nonequilibrium excess quasiparticles, response time is determined by quasiparticles recombination rate. Nanosecond response is probably due to bolometric effect.
|
|
