| Records |
| Author |
Heslinga, D. R.; Shafranjuk, S. E.; van Kempen, H.; Klapwijk, T. M. |
| Title |
Observation of double-gap-edge Andreev reflection at Si/Nb interfaces by point-contact spectroscopy |
Type |
Journal Article |
| Year |
1994 |
Publication |
Phys. Rev. B |
Abbreviated Journal |
Phys. Rev. B |
| Volume |
49 |
Issue |
15 |
Pages |
10484-10494 |
| Keywords |
Nb, Si, Nb-Si, Nb/Si, Si/Nb, Andreev reflection, point-contact spectroscopy |
Abstract  |
Andreev reflection point-contact spectroscopy is performed on a bilayer consisting of 50-nm degenerately doped Si backed with Nb. Due to the short mean free path both injection into and transport across the Si layer are diffusive, in contrast to the ballistic conditions prevailing in clean metal layers. Nevertheless a large Andreev signal is observed in the point-contact characteristics, not reduced by elastic scattering in the Si layer or by interface scattering, but only limited by the transmission coefficient of the metal-semiconductor point contact. Two peaks in the Andreev reflection probability are visible, marking the values of the superconducting energy gap at the interface on the Nb and Si sides. This interpretation is supported by a method of solving the Bogolubov equations analytically using a simplified expression for the variation of the order parameter close to the interface. This observation enables a comparison with theoretical predictions of the gap discontinuity in the proximity effect. It is found that the widely used de Gennes model does not agree with the experimental data. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Physical Society |
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 |
1005 |
| Permanent link to this record |
| |
|
| |
| Author |
González, F. J.; Boreman, G. D. |
| Title |
Comparison of dipole, bowtie, spiral and log-periodic IR antennas |
Type |
Journal Article |
| Year |
2005 |
Publication |
Infrared Physics & Technology |
Abbreviated Journal |
Inf Phys & Technol |
| Volume |
46 |
Issue |
5 |
Pages |
418-428 |
| Keywords |
optical antennas; Microbolometer; Infrared antennas; Antenna efficiency; Antenna-coupled detectors |
| Abstract |
Antenna-coupled microbolometers use planar lithographic antennas to couple infrared radiation into a bolometer with sub-micron dimensions. In this paper four different types of infrared antennas were fabricated on thin grounded-substrates and coupled to microbolometers. Dipole, bowtie, spiral and log-periodic IR antenna-coupled detectors were measured at 10.6 μm and their performance compared. A new method to calculate the radiation efficiency based on the spatial and angular response of infrared antennas is presented and used to evaluate their performance. The calculated radiation efficiency for the dipole, bowtie, spiral and log-periodic IR antennas was 20%, 37%, 25% and 46% respectively. A dipole-length study was performed and shows that the quasistatic value of the effective permittivity accurately describes the incident wavelength in the substrate at infrared frequencies for antennas on a thin substrate. |
| 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 |
739 |
| Permanent link to this record |
| |
|
| |
| Author |
Alda, Javier; Rico-García, José M.; López-Alonso, José M.; Boreman, G. |
| Title |
Optical antennas for nano-photonic applications |
Type |
Journal Article |
| Year |
2005 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotech. |
| Volume |
16 |
Issue |
5 |
Pages |
S230-S234 |
| Keywords |
optical antennas |
| Abstract |
Antenna-coupled optical detectors, also named optical antennas, are being developed and proposed as alternative detection devices for the millimetre, infrared, and visible spectra. Optical and infrared antennas represent a class of optical components that couple electromagnetic radiation in the visible and infrared wavelengths in the same way as radioelectric antennas do at the corresponding wavelengths. The size of optical antennas is in the range of the detected wavelength and they involve fabrication techniques with nanoscale spatial resolution. Optical antennas have already proved and potential advantages in the detection of light showing polarization dependence, tuneability, and rapid time response. They also can be considered as point detectors and directionally sensitive elements. So far, these detectors have been thoroughly tested in the mid-infrared with some positive results in the visible. The measurement and characterization of optical antennas requires the use of an experimental set-up with nanometric resolution. On the other hand, a computation simulation of the interaction between the material structures and the incoming electromagnetic radiation is needed to explore alternative designs of practical 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 |
|
Approved |
no |
| Call Number |
RPLAB @ gujma @ |
Serial |
734 |
| Permanent link to this record |
| |
|
| |
| Author |
Bozyigit, D.; Lang, C.; Steffen, L.; Fink, J. M.; Eichler, C.; Baur, M.; Bianchetti, R.; Leek, P. J.; Filipp, S.; da Silva, M. P.; Blais, A.; Wallraff, A. |
| Title |
Antibunching of microwave-frequency photons observed in correlation measurements using linear detectors |
Type |
Journal Article |
| Year |
2011 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat. Phys. |
| Volume |
7 |
Issue |
2 |
Pages |
154-158 |
| Keywords |
fromIPMRAS |
| Abstract |
At optical frequencies the radiation produced by a source, such as a laser, a black body or a single-photon emitter, is frequently characterized by analysing the temporal correlations of emitted photons using single-photon counters. At microwave frequencies, however, there are no efficient single-photon counters yet. Instead, well-developed linear amplifiers allow for efficient measurement of the amplitude of an electromagnetic field. Here, we demonstrate first- and second-order correlation function measurements of a pulsed microwave-frequency single-photon source integrated on the same chip with a 50/50 beam splitter followed by linear amplifiers and quadrature amplitude detectors. We clearly observe single-photon coherence in first-order and photon antibunching in second-order correlation function measurements of the propagating fields. |
| 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 |
835 |
| Permanent link to this record |
| |
|
| |
| Author |
Smirnov, K. V.; Vachtomin, Y. B.; Ozhegov, R. V.; Pentin, I. V.; Slivinskaya, E. V.; Korneev, A. A.; Goltsman, G. N. |
| Title |
Fiber coupled single photon receivers based on superconducting detectors for quantum communications and quantum cryptography |
Type |
Conference Article |
| Year |
2008 |
Publication |
Proc. SPIE |
Abbreviated Journal |
Proc. SPIE |
| Volume |
7138 |
Issue |
|
Pages |
713827 (1 to 6) |
| Keywords |
SSPD, SNSPD, superconducting single photon detector, ultra-thin superconducting films, optical fiber coupling, ready to use receiver |
| Abstract |
At present superconducting detectors become increasingly attractive for various practical applications. In this paper we present results on the depelopment of fiber coupled receiver systems for the registration of IR single photons, optimized for telecommunication and quantum-cryptography. These receiver systems were developed on the basis of superconducting single photon detectors (SSPD) of VIS and IR wavelength ranges. The core of the SSPD is a narrow ( 100 nm) and long ( 0,5 mm) strip in the form of a meander which is patterned from a 4-nm-thick NbN film (TC=10-11 K, jC= 5-7•106 A/cm2); the sensitive area dimensions are 10×10 μm2. The main problem to be solved while the receiver system development was optical coupling of a single-mode fiber (9 microns in diameter) with the SSPD sensitive area. Characteristics of the developed system at the optical input are as follows: quantum efficiency >10 % (at 1.3 μm), >4 % (at 1.55 μm); dark counts rate ≤1 s-1; duration of voltage pulse ≤5 ns; jitter ≤40 ps. The receiver systems have either one or two identical channels (for the case of carrying out correlation measurements) and are made as an insert in a helium storage Dewar. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Spie |
Place of Publication |
|
Editor |
Tománek, P.; Senderáková, D.; Hrabovský, M. |
| 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 |
1405 |
| Permanent link to this record |
