Home << 1 2 3 4 5 6 7 8 9 10 >> [11–13]
List View
 | 
Citations
 | 
Details
   web
Records
Author Verevkin, A. I.; Ptitsina, N. G.; Chulkova, G. M.; Gol'tsman, G. N.; Gershenzon, E. M.; Yngvesson, K. S.
Title Electron energy relaxation in a 2D channel in AlGaAs-GaAs heterostructures under quasiequilibrium conditions at low temperatures Type Journal Article
Year 1995 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume 61 Issue 7 Pages 591-595
Keywords 2DEG, AlGaAs/GaAs heterostructures
Abstract The energy relaxation time of 2D electrons, Te, has been measured under quasiequilibrium conditions in AlGaAs—GaAs heterojunctions over the temperature range T= 1.5—20 K. At T> 4 K, Te depends only weakly on the temperature, while at T< 4 K 7;'(T) there is a dependence fr; lNT. A linear dependence 7: 1 (T) in the Bloch—-Grfineisen temperature region (T< 5 K) is unambiguous evidence that a piezoacoustic mechanism of an electron—phonon interaction is predominant in the inelastic scattering of electrons. The values of T6 in this temperature range agree very accurately with theoretical results reported by Karpus [Sov. Phys. Semicond. 22 (1988)]. At higher temperatures, where scat—tering by deformation acoustic phonons becomes substantial, there is a significant discrepancy between the experimental and theoretical re-sults.
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 1624
Permanent link to this record
 
 
Author Varyukhin, S. V.; Zakharov, A. A.; Gershenzon, E. M.; Gol'tsman, G. N.; Ptitsina, N. G.; Chulkova, G. M.
Title Low energy excitation in La2CuO4 Type Journal Article
Year 1990 Publication Sverkhprovodimost': Fizika, Khimiya, Tekhnika Abbreviated Journal Sverkhprovodimost': Fizika, Khimiya, Tekhnika
Volume 3 Issue 5 Pages 832-837
Keywords metal-dielectric-La2CuO4, monocrystals
Abstract Measurements of transmission and photoconductivity spectra in submillimeter wave length range as well as of capacity C and conductivity G in the region of acoustic frequencies of metal-dielectric-La2CuO4 system at low temperatures are performed using La2CuO4 monocrystals. Optical spectra posses a threshold character, a sharp decrease of transmission and photocoductivity signal occurs in the energy region hν>1.5 MeV. C(ω,T) and G(ω, T) dependences have a universal form typical of Debye type relaxation processes. Relaxation time dependence is of thermoactivated character τ(T)∼exp(ξ/T) with the gap value ξ≅2 meV. It is assumed that excitations with characteristic energy of ∼2 meV exist in La2CuO4. A possible nature of the detected low-energy excitations is discussed.
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 1688
Permanent link to this record
 
 
Author Voevodin, E. I.; Gershenzon, E. M.; Goltsman, G. N.; Ptitsina, N. G.; Chulkova, G. M.
Title Capture of free holes by charged acceptors in uniaxially deformed Ge Type Journal Article
Year 1988 Publication Fizika i Tekhnika Poluprovodnikov Abbreviated Journal Fizika i Tekhnika Poluprovodnikov
Volume 22 Issue 3 Pages 540-543
Keywords Ge, free holes, capture
Abstract Цель настоящей работы — исследование кинетики примесной фотопрово­димости p-Ge при сильном одноосном сжатии в широком диапазоне изменения интенсивности примесного подсвета, создающего свободные дырки, и опреде­ление сечения каскадного захвата дырок на мелкие заряженные акцепторы в условиях преобладания электрон-фононного механизма потерь энергии.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Russian Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Захват свободных дырок заряженными акцепторами в одноосно деформированном Ge Approved no
Call Number Serial 1698
Permanent link to this record
 
 
Author Verevkin, A.; Zhang, J.; Pearlman, A.; Slysz, W.; Sobolewski, Roman; Korneev, A.; Kouminov, P.; Okunev, O.; Chulkova, G.; Gol'tsman, G.
Title Ultimate sensitivity of superconducting single-photon detectors in the visible to infrared range Type Miscellaneous
Year 2004 Publication ResearchGate Abbreviated Journal ResearchGate
Volume Issue Pages
Keywords NbN SSPD, SNSPD
Abstract We present our quantum efficiency (QE) and noise equivalent power (NEP) measurements of the meandertype ultrathin NbN superconducting single-photon detector in the visible to infrared radiation range. The nanostructured devices with 3.5-nm film thickness demonstrate QE up to~ 10% at 1.3–1.55 µm wavelength, and up to 20% in the entire visible range. The detectors are sensitive to infrared radiation with the wavelengths down to~ 10 µm. NEP of about 2× 10-18 W/Hz1/2 was obtained at 1.3 µm wavelength. Such high sensitivity together with GHz-range counting speed, make NbN photon counters very promising for efficient, ultrafast quantum communications and another applications. We discuss the origin of dark counts in our devices and their ultimate sensitivity in terms of the resistive fluctuations in our superconducting nanostructured devices.
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 Not attributed to any publisher! File name: PR9VervekinSfin_f.doc; Author: JAOLEARY; Last modification date: 2004-02-26 Approved no
Call Number Serial 1751
Permanent link to this record
 
 
Author Gol'tsman, G. N.; Korneev, A.; Rubtsova, I.; Milostnaya, I.; Chulkova, G.; Minaeva, O.; Smirnov, K.; Voronov, B.; Słysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, R.
Title Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications Type Journal Article
Year 2005 Publication Phys. Stat. Sol. (C) Abbreviated Journal Phys. Stat. Sol. (C)
Volume 2 Issue 5 Pages 1480-1488
Keywords NbN SSPD, SNSPD
Abstract We present our progress on the research and development of NbN superconducting single‐photon detectors (SSPD's) for ultrafast counting of near‐infrared photons for secure quantum communications. Our SSPD's operate in the quantum detection mode based on the photon‐induced hotspot formation and subsequent development of a transient resistive barrier across an ultrathin and submicron‐width superconducting stripe. The devices are fabricated from 4‐nm‐thick NbN films and kept in the 4.2‐ to 2‐K temperature range. The detector experimental quantum efficiency in the photon‐counting mode reaches above 40% for the visible light and up to 30% in the 1.3‐ to 1.55‐µm wavelength range with dark counts below 0.01 per second. The experimental real‐time counting rate is above 2 GHz and is limited by our readout electronics. The SSPD's timing jitter is below 18 ps, and the best‐measured value of the noise‐equivalent power (NEP) is 5 × 10–21 W/Hz1/2 at 1.3 µm. In terms of quantum efficiency, timing jitter, and maximum counting rate, our NbN SSPD's significantly outperform semiconductor avalanche photodiodes and photomultipliers in the 1.3‐ to 1.55‐µm range.
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 1610-1634 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1479
Permanent link to this record