| Home | [41–50] << 51 52 53 54 55 56 57 58 59 60 >> [61–70] |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Beck, Matthias; Leiderer, Paul; Kabanov, Viktor V.; Gol'tsman, Gregory; Helm, Manfred; Demsar, Jure | ||||
| Title | Energy-gap dynamics of a superconductor NbN studied by time-resolved terahertz spectroscopy | Type | Abstract | ||
| Year | 2012 | Publication | INIS | Abbreviated Journal  |
INIS |
| Volume | 45 | Issue | 12 | Pages | 1-3 |
| Keywords | NbN energy gap | ||||
| Abstract | Using time-resolved terahertz (THz) spectroscopy we performed direct studies of the photoinduced suppression and recovery of the SC gap in a conventional SC 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 important microscopic constants: the Cooper pair-breaking rate via phonon absorption and the bare quasiparticle recombination rate. From the latter we were able to extract the dimensionless electron-phonon coupling constant, λ=1.1±0.1, in excellent agreement with theoretical estimates. The technique also allowed us to determine the absorbed energy required to suppress SC, which in NbN equals the thermodynamic condensation energy (in cuprates the two differ by an order of magnitude). Finally, we present the first studies of dynamics following resonant excitation with intense narrow band THz pulses tuned to above and below the superconducting gap. These suggest an additional process, particularly pronounced near Tc, that could be attributed to amplification of SC via effective quasiparticle cooling. | ||||
| 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 | Serial | 1383 | |||
| Permanent link to this record | |||||
| Author | Korneeva, Yuliya; Florya, Irina; Vdovichev, Sergey; Moshkova, Mariya; Simonov, Nikita; Kaurova, Natalia; Korneev, Alexander; Goltsman, Gregory | ||||
| Title | Comparison of hot-spot formation in NbN and MoN thin superconducting films after photon absorption | Type | Conference Article | ||
| Year | 2017 | Publication | IEEE Transactions on Applied Superconductivity | Abbreviated Journal |
IEEE Transactions on Applied Superconductiv |
| Volume | 27 | Issue | 4 | Pages | 5 |
| Keywords | Thin film devices, Superconducitng photoncounting devices, Nanowire single-photon detectors | ||||
| Abstract | In superconducting single-photon detectors SSPD the efficiency of local suppression of superconductivity and hotspot formation is controlled by diffusivity and electron-phonon interaction time. Here we selected a material, 3.6-nm-thick MoNx film, which features diffusivity close to those of NbN traditionally used for SSPD fabrication, but with electron-phonon interaction time an order of magnitude larger. In MoNx detectors we study the dependence of detection efficiency on bias current, photon energy, and strip width and compare it with NbN SSPD. We observe non-linear current-energy dependence in MoNx SSPD and more pronounced plateaus in dependences of detection efficiency on bias current which we attribute to longer electronphonon interaction time. |
||||
| 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 @ kovalyuk @ | Serial | 1114 | ||
| Permanent link to this record | |||||
| Author | Trifonov, A.; Tong, C.-Y. E.; Grimes, P.; Lobanov, Y.; Kaurova, N.; Blundell, R.; Goltsman, G. | ||||
| Title | Development of A Silicon Membrane-based Multi-pixel Hot Electron Bolometer Receiver | Type | Conference Article | ||
| Year | 2017 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
| Volume | 27 | Issue | 4 | Pages | 6 |
| Keywords | Multi-pixel, HEB, silicon-on-insulator, horn array | ||||
| Abstract | We report on the development of a multi-pixel Hot Electron Bolometer (HEB) receiver fabricated using silicon membrane technology. The receiver comprises a 2 × 2 array of four HEB mixers, fabricated on a single chip. The HEB mixer chip is based on a superconducting NbN thin film deposited on top of the silicon-on-insulator (SOI) substrate. The thicknesses of the device layer and handling layer of the SOI substrate are 20 μm and 300 μm respectively. The thickness of the device layer is chosen such that it corresponds to a quarter-wave in silicon at 1.35 THz. The HEB mixer is integrated with a bow-tie antenna structure, in turn designed for coupling to a circular waveguide, |
||||
| 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 @ kovalyuk @ | Serial | 1111 | ||
| Permanent link to this record | |||||
| Author | Tong, C.-Y. E.; Meledin, D.; Loudkov, D.; Blundell, R.; Erickson, N.; Kawamura, J.; Mehdi, I.; Gol’tsman, G. | ||||
| Title | A 1.5 THz Hot-Electron Bolometer mixer operated by a planar diode based local oscillator | Type | Conference Article | ||
| Year | 2003 | Publication | IEEE MTT-S Int. Microwave Symp. Digest | Abbreviated Journal |
IEEE MTT-S Int. Microwave Symp. Digest |
| Volume | 2 | Issue | Pages | 751-754 | |
| Keywords | waveguide NbN HEB mixers | ||||
| Abstract | We have developed a 1.5 THz superconducting NbN Hot-Electron Bolometer mixer. It is operated by an all-solid-state Local Oscillator comprising of a cascade of 4 planar doublers following an MMIC based W-band power amplifier. The threshold available pump power is estimated to be 1 /spl mu/W. | ||||
| Address | Philadelphia, PA, USA | ||||
| 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 | Serial | 1516 | |||
| Permanent link to this record | |||||
| Author | Matyushkin, Yakov; Fedorov, Georgy; Moskotin, Maksim; Danilov, Sergey; Ganichev, Sergey; Goltsman, Gregory | ||||
| Title | Gate-mediated helicity sensitive detectors of terahertz radiation with graphene-based field effect transistors | Type | Abstract | ||
| Year | 2020 | Publication | Graphene and 2dm Virt. Conf. | Abbreviated Journal |
Graphene and 2DM Virt. Conf. |
| Volume | Issue | Pages | |||
| Keywords | single layer graphene, SLG, CVD, plasmons, FET | ||||
| Abstract | Closing of the so-called terahertz gap results in an increased demand for optoelectronic devices operating in the frequency range from 0.1 to 10 THz. Active plasmonic in field effect devices based on high-mobility two-dimensional electron gas (2DEG) opens up opportunities for creation of on-chip spectrum [1] and polarization [2] analysers. Here we show that single layer graphene (SLG) grown using CVD method can be used for an all-electric helicity sensitive polarization broad analyser of THz radiation. Allourresults show plasmonic nature of response. Devices are made in a configuration ofa field-effect transistor (FET) with a graphene channel that has a length of 2 mkm and a width of 5.5 mkm. Response of opposite polarity to clockwise and anticlockwise polarized radiation is due to special antenna design (see Fig.1c) as follow works [2,3]. Our approaches can be extrapolated to other 2D materials and used as a tool to characterize plasmonic excitations in them. [1]Bandurin, D. A., etal.,Nature Communications, 9(1),(2018),1-8.[2]Drexler, C.,etal.,Journal of Applied Physics, 111(12),(2012),124504.[3]Gorbenko, I. V.,et al.,physica status solidi (RRL)–Rapid Research Letters, 13(3),(2019),1800464. | ||||
| Address | Grenoble, France | ||||
| 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 | Graphene and 2dm Virtual Conference & Expo | ||
| Notes | Approved | no | |||
| Call Number | Serial | 1743 | |||
| Permanent link to this record | |||||