| 1. |
- Lemzyakov, S., et al.
(författare)
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Experimental study of a SINIS detector response time at 350 GHz signal frequency
- 2018
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 969:1
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Konferensbidrag (refereegranskat)abstract
- Response time constant of a SINIS bolometer integrated in an annular ring antenna was measured at a bath temperature of 100 mK. Samples comprising superconducting aluminium electrodes and normal-metal Al/Fe strip connected to electrodes via tunnel junctions were fabricated on oxidized Si substrate using shadow evaporation. The bolometer was illuminated by a fast black-body radiation source through a band-pass filter centered at 350 GHz with a passband of 7 GHz. Radiation source is a thin NiCr film on sapphire substrate. For rectangular 10÷100 μs current pulse the radiation front edge was rather sharp due to low thermal capacitance of NiCr film and low thermal conductivity of substrate at temperatures in the range 1-4 K. The rise time of the response was ∼1-10 μs. This time presumably is limited by technical reasons: high dynamic resistance of series array of bolometers and capacitance of a long twisted pair wiring from SINIS bolometer to a room-Temperature amplifier.
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| 2. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Cryogenic Mimim and Simis Microwave Detectors
- 2020
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Ingår i: Proceedings - 2020 7th All-Russian Microwave Conference, RMC 2020. ; , s. 25-27
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Konferensbidrag (refereegranskat)abstract
- Microwave detectors of the Metal-Insulator-Metal-Insulator-Metal (MIMIM) structure and the Superconductor-Insulator-Metal-Insulator-Superconductor (SIMIS) structure have been designed, fabricated and investigated. The difference of such samples was in external electrodes, MIMIM uses copper external electrodes, while SIMIS uses aluminum. Identical in dimensions MIMIM and SIMIS samples have been fabricated and experimentally studied in the temperature range of 0.1-2.7 K. Voltage and current response were measured at 300 GHz external irradiation using Backward Wave Oscillator (BWO). According to our estimates, the MIMIM current responsivity is 1.1·103 A/W in the case of a photon response and 4·104 A/W in the case of a bolometric response. The estimated noise equivalent power is in the range 2.5·10 18 W/v Hz to 1.2·10-19 W/vHz.
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| 3. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Electrical and optical properties of a bolometer with a suspended absorber and tunneling-current thermometers
- 2017
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 110:24
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a bolometer with a suspended normal-metal absorber connected to superconducting leads via tunneling barriers. Such an absorber has reduced heat losses to the substrate, which greatly increases the responsivity of the bolometer to over 10(9) V/W at 75 mK when measured by dc Joule heating of the absorber. For high-frequency experiments, the bolometers have been integrated in planar twin-slot and log-periodic antennas. At 300GHz and 100 mK, the bolometer demonstrates the voltage and current response of 3 x 10(8) V/W and 1.1 x 10(4) A/W, respectively, corresponding to the quantum efficiency of similar to 15 electrons per photon. An effective thermalization of electrons in the absorber favors the high quantum efficiency. We also report on how the in-plane-and transverse magnetic fields influence the device characteristics.
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| 4. |
- Tarasov, Michael, et al.
(författare)
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Non-Thermal Absorption and Quantum Efficiency of SINIS Bolometer
- 2021
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 31:5
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Tidskriftsartikel (refereegranskat)abstract
- We study mechanisms of absorption in two essentially different types of superconductor-insulator-normal metal-insulator-superconductor (SINIS) bolometers with absorber directly placed on Si wafer and with absorber suspended above the substrate. The figure of merit for quantum photon absorption is quantum efficiency equal to the number of detected electrons for one photon. The efficiency of absorption is dramatically dependent on phonon losses to substrate and electrodes, and electron energy losses to electrodes through tunnel junctions. The maximum quantum efficiency can approach n = hf/kT = 160 at f = 350 GHz T = 0.1 K, and current responsivity dI/dP = e/kT in quantum gain bolometer case, contrary to photon counter mode with quantum efficiency of n = 1 and responsivity dI/dP = e/hf. In experiments, we approach intrinsic quantum efficiency up to n = 80 electrons per photon in bolometer with suspended absorber, contrary to quantum efficiency of about one for absorber on the substrate. In the case of suspended Cu and Pd absorber, Kapitsa resistance protect from power leak to Al electrodes.
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| 5. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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SINIS bolometer with a suspended absorber
- 2018
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 969:1
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Konferensbidrag (refereegranskat)abstract
- We have developed a Superconductor-Insulator-Normal Metal-Insulator-Superconductor (SINIS) bolometer with a suspended normal metal bridge. The suspended bridge acts as a bolometric absorber with reduced heat losses to the substrate. Such bolometers were characterized at 100-350 mK bath temperatures and electrical responsivity of over 10 9 V/W was measured by dc heating the absorber through additional contacts. Suspended bolometers were also integrated in planar twin-slot and log-periodic antennas for operation in the submillimetre-band of radiation. The measured voltage response to radiation at 300 GHz and at 100 mK bath temperature is 3∗10 8 V/W and a current response is 1.1∗10 4 A/W which corresponds to a quantum efficiency of ∼15 electrons per photon. An important feature of such suspended bolometers is the thermalization of electrons in the absorber heated by optical radiation, which in turn provides better quantum efficiency. This has been confirmed by comparison of bolometric response to dc and rf heating. We investigate the performance of direct SN traps and NIS traps with a tunnel barrier between the superconductor and normal metal trap. Increasing the volume of superconducting electrode helps to reduce overheating of superconductor. Influence of Andreev reflection and Kapitza resistance, as well as electron-phonon heat conductivity and thermal conductivity of N-wiring are estimated for such SINIS devices.
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| 6. |
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| 7. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Optical response of a cold-electron bolometer array
- 2010
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Ingår i: JETP Letters. - 1090-6487 .- 0021-3640. ; 92:6, s. 416-420
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Tidskriftsartikel (refereegranskat)abstract
- A multielement bolometric receiver system has been developed to measure the power and polarization of radiation at a calculated frequency of 345 GHz. Arrays of ten series-parallel connected cold-electron bolometers have been pairwise integrated into orthogonal ports of a cross-slot antenna. Arrays are connected in parallel in the high-frequency input signal and in series in the output signal, which is measured at a low frequency, and in a dc bias. Such an array makes it possible to increase the output resistance by two orders of magnitude as compared to an individual bolometer under the same conditions of high-frequency matching and to optimize the matching with the JFET amplifier impedance up to dozens of megohms. Parallel connection ensures matching of the input signal to the cross-slot antenna with an impedance of 30 Omega on a massive silicon dielectric lens. At a temperature of 100 mK, a response to the thermal radiation of a thermal radiation source with an emissivity of 0.3, which covers the input aperture of the antenna and is heated to 3 K, is 25 mu V/K. Taking into account real noise, the optical fluctuation dc sensitivity is 5 mK, the estimated sensitivity corresponding to the noise of the amplifier is about 10(-4) K/Hz(1/2), and the noise-equivalent power is about (1-5) x 10(-17) W/Hz(1/2).
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| 8. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Optical Response of a Cold-Electron Bolometer Array Integrated in a 345-GHz Cross-Slot Antenna
- 2011
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 21:6, s. 3635-3639
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Tidskriftsartikel (refereegranskat)abstract
- Two series/parallel arrays of ten cold-electronbolometers with superconductor–insulator–normal tunnel junctionswere integrated in orthogonal ports of a cross-slot antenna.To increase the dynamic range of the receiver, all single bolometersin an array are connected in parallel for the microwavesignal by capacitive coupling. To increase the output response,bolometers are connected in series for dc bias. With the measuredvoltage-to-temperature response of 8.8 μV/mK, absorbervolume of 0.08 μm3, and output noise of about 10 nV/Hz1/2,we estimated the dark electrical noise equivalent power (NEP)as NEP = 6∗ 10−18 W/Hz1/2. The optical response down toNEP = 2∗ 10−17 W/Hz1/2 was measured using a hot/cold loadas a radiation source and a sample temperature down to 100 mK.The fluctuation sensitivity to the radiation source temperature is1.3 ∗ 10−4 K/Hz1/2. A dynamic range over 43 dB was measuredusing a backward-wave oscillator, a variable polarization gridattenuator, and cold filters/attenuators.
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| 9. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Power Load and Temperature Dependence of Cold-Electron Bolometer Optical Response at 350 GHz
- 2014
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 24:6, s. 1-
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Tidskriftsartikel (refereegranskat)abstract
- Cold-electron bolometers (CEBs) integrated with twin-slot antennas have been designed and fabricated. Optical response was measured at bath temperatures of 0.06 to 3 K using blackbody radiation source at temperatures of 3 to 15 K. The responsivity of 0.3 * 10(9) V/W was measured at 2.7-K blackbody temperature that is close to the temperature of the cosmic microwave background. Optical measurements indicate quasi-optical coupling efficiency of up to 60% at low phonon temperature and low signal level. Estimations for bolometer responsivity were made for practical range of bath temperatures and blackbody radiation temperatures. The estimated ultimate dark responsivity at 100-mK bath temperature can approach S-V = 10(10) V/W and reduces down to 1.1 * 10(8) V/W at 300 mK for a device with absorber volume of 5 * 10(-20) m(3).
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| 10. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Quantum Efficiency of Cold Electron Bolometer Optical Response
- 2015
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Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 5:1, s. 44-48
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present the measurements of optical response dependence on power load of a Cold Electron Bolometer integrated in a twin slot antenna. These measurements are also compared to the models of the bolometer limit and the photon counter limit. The responsivity of 0.22*10^9 V/W was measured at 0.22 pW radiation power from a black body at 3.5 K. According to our estimations, for optimized device the voltage responsivity at 100 mK electron temperature can approach Sv=10^10 V/W for power load below 0.1 pW and decreases down to 10^7 V/W at 300 mK for 5 pW signal power in a sample with absorber volume of 5*10^-20 m^3. In the case of low bath temperatures and high applied RF power the changes of tunneling current, dynamic resistance and voltage response are explained by non-thermal energy distribution of excited electrons. Distribution of excited electrons in such system at lower temperatures can be of non-Fermi type, hot electrons with energies of the order of 1 K tunnel from normal metal absorber to superconductor instead of relaxing down to thermal energy kTe in absorber before tunneling. This effect can reduce quantum efficiency of the bolometer at 350 GHz from hf/kTph>100 in ideal case down to single electron per absorbed photon (Q.Eff=1) in the high power case. Methods of preserving high quantum efficiency are discussed.
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