| |
Records |
Links |
|
Author |
Tikhonov, V. V.; Polyakova, O. N.; Gol’tsman, G. N.; Dzardanov, A. L.; Boyarskiy, D. A. |
|
| |
Title |
Determination of dielectric properties of ore minerals in the microwave band |
Type |
Journal Article |
| |
Year |
2008 |
Publication |
Radiophys. Quant. Electron. |
Abbreviated Journal |
Radiophys. Quant. Electron. |
|
| |
Volume |
51 |
Issue |
12 |
Pages |
966-974 |
|
| |
Keywords  |
ore complex permittivity, chalcopyrite, magnetite, sphalerite, labradorite |
|
| |
Abstract |
We consider a method for determining the complex dielectric permittivity of ore and nonmetal minerals in the microwave band of electromagnetic radiation. The results of measuring the reflectivity and transmittivity of chalcopyrite, magnetite, sphalerite, and labradorite samples in the frequency range 77–300 GHz are presented. A method for calculation of the complex dielectric permittivity of minerals on the basis of the obtained experimental data is proposed. The approximation formulas for calculation of the complex dielectric permittivity of the studied minerals are given. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0033-8443 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1404 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Kahl, O.; Ferrari, S.; Kovalyuk, V.; Goltsman, G. N.; Korneev, A.; Pernice, W. H. P. |
|
| |
Title |
Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths |
Type |
Journal Article |
| |
Year |
2015 |
Publication |
Sci. Rep. |
Abbreviated Journal |
Sci. Rep. |
|
| |
Volume |
5 |
Issue |
|
Pages |
10941 (1 to 11) |
|
| |
Keywords |
optical waveguides; waveguide integrated SSPD; waveguide SSPD; nanophotonics |
|
| |
Abstract |
Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present efficiencies close to unity at 1550nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noiseequivalent powers in the 10–19W/Hz–1/2 range and the timing jitter is as low as 35ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:26061283; PMCID:PMC4462017 |
Approved |
no |
|
| |
Call Number |
RPLAB @ kovalyuk @ |
Serial |
946 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Tuchak, A. N.; Gol’tsman, G. N.; Kitaeva, G. K.; Penin, A. N.; Seliverstov, S. V.; Finkel, M. I.; Shepelev, A. V.; Yakunin, P. V. |
|
| |
Title |
Generation of nanosecond terahertz pulses by the optical rectification method |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
JETP Lett. |
Abbreviated Journal |
JETP Lett. |
|
| |
Volume |
96 |
Issue |
2 |
Pages |
94-97 |
|
| |
Keywords |
optical rectification, lithium niobate crystal |
|
| |
Abstract |
The possibility of the generation of quasi-cw terahertz radiation by the optical rectification method for broad-band Fourier unlimited nanosecond laser pulses has been experimentally demonstrated. The broadband radiation of a LiF dye-center laser is used as a pump source of a nonlinear optical oscillator. The energy efficiency of terahertz optical frequency conversion in a periodically polarized lithium niobate crystal is 4 × 10−9 at a pump power density of 7 MW/cm2. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-3640 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1377 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Nikogosyan, A. S.; Martirosyan, R. M.; Hakhoumian, A. A.; Makaryan, A. H.; Tadevosyan, V. R.; Goltsman, G. N.; Antipov, S. V. |
|
| |
Title |
Effect of absorption on the efficiency of terahertz radiation generation in the metal waveguide partially filled with nonlinear crystal LiNbO3, DAST or ZnTe |
Type |
Journal Article |
| |
Year |
2019 |
Publication |
J. Contemp. Phys. |
Abbreviated Journal |
J. Contemp. Phys. |
|
| |
Volume |
54 |
Issue |
1 |
Pages |
97-104 |
|
| |
Keywords |
nonlinear crystal, THz, waveguide |
|
| |
Abstract |
The influence of terahertz (THz) radiation absorption on the efficiency of generation of coherent THz radiation in the system ‘nonlinear-optical crystal partially filling the cross section of a rectangular metal waveguide’ has been investigated. The efficiency of the nonlinear frequency conversion of optical laser radiation to the THz range depends on the loss in the system and the fulfillment of the phase-matching (FM) condition in a nonlinear crystal. The method of partially filling of a metal waveguide with a nonlinear optical crystal is used to ensure phase matching. The phase matching is achieved by numerical determination of the thickness of the nonlinear crystal, that is the degree of partial filling of the waveguide. The attenuation of THz radiation caused by losses both in the metal walls of the waveguide and in the crystal was studied, taking into account the dimension of the cross section of the waveguide, the degree of partial filling, and the dielectric constant of the crystal. It is shown that the partial filling of the waveguide with a nonlinear crystal results in an increase in the efficiency of generation of THz radiation by an order of magnitude, owing to the decrease in absorption. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1068-3372 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1289 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Beck, M.; Rousseau, I.; Klammer, M.; Leiderer, P.; Mittendorff, M.; Winnerl, S.; Helm, M.; Gol'tsman, G.N.; Demsar, J. |
|
| |
Title |
Transient increase of the energy gap of superconducting NbN thin films excited by resonant narrow-band terahertz pulses |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Phys. Rev. Lett. |
Abbreviated Journal |
Phys. Rev. Lett. |
|
| |
Volume |
110 |
Issue |
26 |
Pages |
267003 (1 to 5) |
|
| |
Keywords |
NbN thin films, energy gap |
|
| |
Abstract |
Observations of radiation-enhanced superconductivity have thus far been limited to a few type-I superconductors (Al, Sn) excited at frequencies between the inelastic scattering rate and the superconducting gap frequency 2Delta/h. Utilizing intense, narrow-band, picosecond, terahertz pulses, tuned to just below and above 2Delta/h of a BCS superconductor NbN, we demonstrate that the superconducting gap can be transiently increased also in a type-II dirty-limit superconductor. The effect is particularly pronounced at higher temperatures and is attributed to radiation induced nonthermal electron distribution persisting on a 100 ps time scale. |
|
| |
Address |
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457, Germany |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0031-9007 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:23848912 |
Approved |
no |
|
| |
Call Number |
|
Serial |
1370 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Beck, M.; Klammer, M.; Lang, S.; Leiderer, P.; Kabanov, V. V.; Gol'tsman, G. N.; Demsar, J. |
|
| |
Title |
Energy-gap dynamics of superconducting NbN thin films studied by time-resolved terahertz spectroscopy |
Type |
Journal Article |
| |
Year |
2011 |
Publication |
Phys. Rev. Lett. |
Abbreviated Journal |
Phys. Rev. Lett. |
|
| |
Volume |
107 |
Issue |
17 |
Pages |
4 |
|
| |
Keywords |
NbN thin film, energy gap dynamics |
|
| |
Abstract |
Using time-domain terahertz spectroscopy we performed direct studies of the photoinduced suppression and recovery of the superconducting gap in a conventional BCS superconductor NbN. Both processes are found to be strongly temperature and excitation density dependent. The analysis of the data with the established phenomenological Rothwarf-Taylor model enabled us to determine the bare quasiparticle recombination rate, the Cooper pair-breaking rate and the electron-phonon coupling constant, λ=1.1±0.1, which is in excellent agreement with theoretical estimates. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
RPLAB @ gujma @ |
Serial |
641 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zorin, M.; Milostnaya, I.; Gol'tsman, G. N.; Gershenzon, E. M. |
|
| |
Title |
Fast NbN superconducting switch controlled by optical radiation |
Type |
Journal Article |
| |
Year |
1997 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
|
| |
Volume |
7 |
Issue |
2 |
Pages |
3734-3737 |
|
| |
Keywords |
NbN superconducting switch |
|
| |
Abstract |
The switching time and the optical control power of the NbN superconducting switch have been measured. The device is based on the ultrathin film 5-8 nm thick patterned as a structure of several narrow parallel strips (/spl sim/1 /spl mu/m wide) connected to wide current leads. The current-voltage characteristic of the switch at temperature 4.2 K demonstrated a hysteresis due to DC current self-heating. We studied the superconducting-to-resistive state transition induced by both optical and bias-current excitations. The optical pulse duration was /spl sim/20 ps and the rise time of the current step was determined to be less than 50 ps. The optical pulse was delivered to the switch by the semiconductor laser through an optical fiber. We found that the measured switching time is less than the duration of the optical excitation. The threshold optical power density does not exceed 3/spl middot/10/sup 3/ W/cm/sup 2/. The proposed device can be used in the fiber input of LTS rapid single flux quantum circuits. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1051-8223 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1596 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zolotov, P.; Semenov, A.; Divochiy, A.; Goltsman, G. |
|
| |
Title |
A comparison of VN and NbN thin films towards optimal SNSPD efficiency |
Type |
Journal Article |
| |
Year |
2021 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
|
| |
Volume |
31 |
Issue |
5 |
Pages |
1-4 |
|
| |
Keywords |
NbN SSPD, SNSPD, WSi |
|
| |
Abstract |
Based on early phenomenological ideas about the operation of superconducting single-photon detectors (SSPD or SNSPD), it was expected that materials with a lower superconducting gap should perform better in the IR range. The plausibility of this concept could be checked using two popular SSPD materials – NbN and WSi films. However, these materials differ strongly in crystallographic structure (polycrystalline B1 versus amorphous), which makes their dependence on disorder different. In our work we present a study of the single-photon response of SSPDs made from two disordered B1 structure superconductors – vanadium nitride and niobium nitride thin films. We compare the intrinsic efficiency of devices made from films with different sheet resistance values. While both materials have a polycrystalline structure and comparable diffusion coefficient values, VN films show metallic behavior over a wide range of sheet resistance, in contrast to NbN films with an insulator-like temperature dependence of resistivity, which may be partially due to enhanced Coulomb interaction, leading to different starting points for the normal electron density of states. The results show that even though VN devices are more promising in terms of theoretical predictions, their optimal performance was not reached due to lower values of sheet resistance. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1051-8223 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1223 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lusche, R.; Semenov, A.; Ilin, K.; Siegel, M.; Korneeva, Y.; Trifonov, A.; Korneev, A.; Goltsman, G.; Vodolazov, D.; Hübers, H.-W. |
|
| |
Title |
Effect of the wire width on the intrinsic detection efficiency of superconducting-nanowire single-photon detectors |
Type |
Journal Article |
| |
Year |
2014 |
Publication |
J. Appl. Phys. |
Abbreviated Journal |
J. Appl. Phys. |
|
| |
Volume |
116 |
Issue |
4 |
Pages |
043906 (1 to 9) |
|
| |
Keywords |
NbN SSPD, SNSPD, TaN |
|
| |
Abstract |
A thorough spectral study of the intrinsic single-photon detection efficiency in superconducting TaN and NbN nanowires with different widths has been performed. The experiment shows that the cut-off of the intrinsic detection efficiency at near-infrared wavelengths is most likely controlled by the local suppression of the barrier for vortex nucleation around the absorption site. Beyond the cut-off quasi-particle diffusion in combination with spontaneous, thermally activated vortex crossing explains the detection process. For both materials, the reciprocal cut-off wavelength scales linearly with the wire width where the scaling factor agrees with the hot-spot detection model. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-8979 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1357 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sclafani, M.; Marksteiner, M.; Keir, F. M. L.; Divochiy, A.; Korneev, A.; Semenov, A.; Gol'tsman, G.; Arndt, M. |
|
| |
Title |
Sensitivity of a superconducting nanowire detector for single ions at low energy |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Nanotechnol. |
Abbreviated Journal |
Nanotechnol. |
|
| |
Volume |
23 |
Issue |
6 |
Pages |
065501 (1 to 5) |
|
| |
Keywords |
NbN SSPD, SNSPD, superconducting single ion detector, SSID, SNSID |
|
| |
Abstract |
We report on the characterization of a superconducting nanowire detector for ions at low kinetic energies. We measure the absolute single-particle detection efficiency eta and trace its increase with energy up to eta = 100%. We discuss the influence of noble gas adsorbates on the cryogenic surface and analyze their relevance for the detection of slow massive particles. We apply a recent model for the hot-spot formation to the incidence of atomic ions at energies between 0.2 and 1 keV. We suggest how the differences observed for photons and atoms or molecules can be related to the surface condition of the detector and we propose that the restoration of proper surface conditions may open a new avenue for SSPD-based optical spectroscopy on molecules and nanoparticles. |
|
| |
Address |
Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, Vienna, Austria |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0957-4484 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:22248823 |
Approved |
no |
|
| |
Call Number |
|
Serial |
1380 |
|
| Permanent link to this record |
