Records |
Author |
Baselmans, J. J. A.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; de Korte, P. A. J.; Voronov, B.; Gol'tsman, G. |
Title |
Noise performance of NbN hot electron bolometer mixers at 2.5 THz and its dependence on the contact resistance |
Type |
Conference Article |
Year |
2003 |
Publication |
Proc. 14th Int. Symp. Space Terahertz Technol. |
Abbreviated Journal |
Proc. 14th Int. Symp. Space Terahertz Technol. |
Volume |
|
Issue |
|
Pages |
11-19 |
Keywords |
NbN HEB mixers |
Abstract |
NbN hot electron bolometer mixers (HEBM) are at this moment the best heterodyne receivers for frequencies above 1 Thz. However, the fabrication procedure of these devices is such that the quality of the interface between the NbN superconducting film and the contact structure is not under good control. The result is a low transparency interface between the bolometer itself and the contact/antenna structure. In this paper we report a detailed experimental study on a novel idea to increase the transparency of this interface. This leads to a record sensitivity and more reproducible performance. We compare identical bolometers, coupled with a spiral antenna, with different NbN bolometer-contact pad interfaces. We find that cleaning the NbN interface alone results in an increase in the noise temperature. However, cleaning the NbN interface and adding a thin additional superconductor prior to the gold contact deposition improves the noise temperature of the HEBm with more than a factor of 2. A device with a contact pad on top of an in-situ cleaned NbN film consisting of 10 nm of NbTiN and 40 nm of gold has a DSB noise temperature of 1050 K at 2.5 THz. |
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 |
1497 |
Permanent link to this record |
|
|
|
Author |
Baubert, J.; Salez, M.; Delorme, Y.; Pons, P.; Goltsman, G.; Merkel, H.; Leconte, B. |
Title |
Membrane-based HEB mixer for THz applications |
Type |
Conference Article |
Year |
2003 |
Publication |
Proc. SPIE |
Abbreviated Journal |
Proc. SPIE |
Volume |
5116 |
Issue |
|
Pages |
551-562 |
Keywords |
membrane NbN HEB mixers, heterodyne receiver, stress-less membrane, coupling efficiency, submillimeter-waves frequency, low-cost space applications |
Abstract |
We report in this paper a new concept for 2.7 THz superconducting Niobium nitride (NbN) Hot-Electron Bolometer mixer (HEB). The membrane process was developped for space telecommnunication applications a few years ago and the HEB mixer concept is now considered as the best choice for low-noise submillimeter-wave frequency heterodyne receivers. The idea is then to join these two technologies. The novel fabrication scheme is to fabricate a NbN HEB mixer on a 1 μm thick stress-less Si3N4/SiO2 membrane. This seems to present numerous improvements concerning : use at higher RF frequencies, power coupling efficiency, HEB mixer sensitivity, noise temperature, and space applications. This work is to be continued within the framework of an ESA TRP project, a 2.7 THz heterodyne camera with numerous applications including a SOFIA airborne receiver. This paper presents the whole fabrication process, the validation tests and preliminary results. Membrane-based HEB mixer theory is currently being investigated and further tests such as heterodyne and Fourier transform spectrometry measurement are planed shortly. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
SPIE |
Place of Publication |
|
Editor |
Chiao, J.-C.; Varadan, V.K.; Cané, C. |
Language |
|
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
Smart Sensors, Actuators, and MEMS |
Notes |
|
Approved |
no |
Call Number |
|
Serial |
1520 |
Permanent link to this record |
|
|
|
Author |
Baubert, J.; Salez, M.; Merkel, H.; Pons, P.; Cherednichenko, S.; Lecomte, B.; Drakinsky, V.; Goltsman, G.; Leone, B. |
Title |
IF gain bandwidth of membrane-based NbN hot electron bolometers for SHAHIRA |
Type |
Journal Article |
Year |
2005 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
Volume |
15 |
Issue |
2 |
Pages |
507-510 |
Keywords |
NbN HEB mixers, applications |
Abstract |
SHAHIRA (Submm Heterodyne Array for HIgh-speed Radio Astronomy) is a project supported by the European Space Agency (ESA) and is designed to fly on the SOFIA observatory. A quasi-optic design has been chosen for 2.5/2.7 THz and 4.7 THz, for hydroxyde radical OH, deuterated hydrogen HD and neutral atomic oxygen OI lines observations. Hot electron bolometers (HEBs) have been processed on 1 /spl mu/m thick SiO/sub 2//Si/sub 3/N/sub 4/ stress-less membranes. In this paper we analyse the intermediate frequency (IF) gain bandwidth from the theoretical point of view, and compare it to measurements. |
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 |
1558-2515 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
|
Approved |
no |
Call Number |
|
Serial |
1468 |
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 |
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 |
Miscellaneous |
Year |
2011 |
Publication |
arXiv |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
|
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, \lambda = 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 |
Duplicated as 641 |
Approved |
no |
Call Number |
|
Serial |
1388 |
Permanent link to this record |