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Author Khosropanah, Pourya
Title NbN and NbTiN hot electron bolometer THz mixers Type Book Whole
Year 2003 Publication Chalmers University of Technology Abbreviated Journal
Volume Issue Pages
Keywords HEB mixer, hot electron bolometer mixer, NbN, NbTiN, superconducting detector, heterodyne receiver, THz mixer, submillimeter mixer, quasioptical receiver, double slot antenna, twin slot antenna, spiral antenna, receiver noise, FTS, Fourier Transform Spectrometer
Abstract The thesis reports the development of Hot Electron Bolometer (HEB) mixers for radio astronomy heterodyne receivers in THz frequency range. Part of this work is the fabrication of HEB devices, which are based on NbN or NbTiN superconducting thin films (â‰<a4>5 nm). They are integrated with wideband spiral or double-slot planar antennas. The mixer chips are incorporated into a quasi-optical receiver. The experimental part of this work focuses on the characterization of the receiver as a whole, and the HEB mixers as a part. Double side band receiver noise temperature and the IF bandwidth are reported for frequencies from 0.7 THz up to 2.6 THz. The spectrum of the direct response of HEB integrated with dierent antennas are measured using Fourier Transform Spectrometer (FTS). The effect of the bolometer size on total receiver performance and the LO power requirements is also discussed. A high-yield and reliable process for fabrication of NbN HEB mixers have been achieved. Over 100 devices with different bolometer geometry, film property and also different antennas have been fabricated and measured. The measured data enables us to discuss the impact of different parameters to the receiver overall performance.

This work has provided NbN HEB mixers to the following receivers:

TREND (Terahertz REceiver with NbN HEB Device) operating at 1.25-1.5 THz, installed in AST/RO Submillimeter Wave Telescope, Amundsen/Scott South Pole Station, in 2002-2003.

Band 6-low (1.410-1.700 THz) and 6-high (1.700-1.920 THz) of the HIFI (Heterodyne Instrument for Far Infra-red) in the Herschel Space Observatory, due to launch in 2007 by ESA (European Space Agency).

Besides, there has been continuous efforts to develop better models to explain the mixer performance more accurately. They are based on two temperature model for electrons and phonons and solving one-dimensional heat balance equations along the bolometer. The principles of these models are illustrated and the calculated results are compared with measured data.
Address
Corporate Author Thesis Ph.D. thesis
Publisher Chalmers University of Technology Place of Publication Göteborg Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 910
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Author Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Gol'tsman, G.; Svechnikov, S.; Gershenzon, E.
Title Noise temperature and local oscillator power requirement of NbN phonon-cooled hot electron bolometric mixers at terahertz frequencies Type Journal Article
Year 1998 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 73 Issue 19 Pages 2814-2816
Keywords NbN HEB mixers, noise temperature, local oscillator power
Abstract In this letter, the noise performance of NbN-based phonon-cooled hot electron bolometric quasioptical mixers is investigated in the 0.55–1.1 THz frequency range. The best results of the double-sideband <cd><2018>DSB<cd><2019> noise temperature are: 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz, and 1250 K at 1.1 THz. The water vapor in the signal path causes significant contribution to the measured receiver noise temperature around 1.1 THz. The devices are made from 3-nm-thick NbN film on high-resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are typically 0.2Ï«2 um. The amount of local oscillator power absorbed in the bolometer is less than 100 nW.
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 (up) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 911
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Author Klapwijk, T. M.; Barends, R.; Gao, J. R.; Hajenius, M.; Baselmans, J. J. A.
Title Improved superconducting hot-electron bolometer devices for the THz range Type Conference Article
Year 2004 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 5498 Issue Pages 129-139
Keywords HEB mixer distributed model, numerical model
Abstract Improved and reproducible heterodyne mixing (noise temperatures of 950 K at 2.5 THz) has been realized with NbN based hot-electron superconducting devices with low contact resistances. A distributed temperature numerical model of the NbN bridge, based on a local electron and a phonon temperature, has been used to understand the physical conditions during the mixing process. We find that the mixing is predominantly due to the exponential rise of the local resistivity as a function of electron temperature.
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 (up) ISBN Medium
Area Expedition Conference
Notes Invited talk, Recommended by Klapwijk Approved no
Call Number Serial 912
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Author Gurevich, A. Vl.; Mints, R. G.
Title Self-heating in normal metals and superconductors Type Journal Article
Year 1987 Publication Rev. Mod. Phys. Abbreviated Journal
Volume 59 Issue 4 Pages 941-1000
Keywords HEB, Joule self-heating effect
Abstract This review is devoted to the physics of current-carrying superconductors and normal metals having two or more stable states sustained by Joule self-heating. The creation, propagation, and localization of electrothermal domains and switching waves leading to the transition from one stable state to another in uniform and nonuniform samples are treated in detail. The connection between thermal bistability and hysteresis, dropping and stepped current-voltage characteristics, self-induced oscillations of current and voltage, selfreplication of electrothermal domains, and the formation of periodic and stochastic resistive structures are considered.
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 (up) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 917
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Author Pekker, David; Shah, Nayana; Sahu, Mitrabhanu; Bezryadin, Alexey; Goldbart, Paul M.
Title Stochastic dynamics of phase-slip trains and superconductive-resistive switching in current-biased nanowires Type Journal Article
Year 2009 Publication Phys. Rev. B Abbreviated Journal
Volume 80 Issue Pages 214525 (1 to 17)
Keywords superconducting nanowire, phase-slip, order parameter, HEB distributed model, HEB model
Abstract Superconducting nanowires fabricated via carbon-nanotube templating can be used to realize and study quasi-one-dimensional superconductors. However, measurement of the linear resistance of these nanowires have been inconclusive in determining the low-temperature behavior of phase-slip fluctuations, both quantal and thermal. Thus, we are motivated to study the nonlinear current-voltage characteristics in current-biased nanowires and the stochastic dynamics of superconductive-resistive switching, as a way of probing phase-slip events. In particular, we address the question: can a single phase-slip event occurring somewhere along the wire—during which the order-parameter fluctuates to zero—induce switching, via the local heating it causes? We explore this and related issues by constructing a stochastic model for the time evolution of the temperature in a nanowire whose ends are maintained at a fixed temperature. We derive the corresponding master equation as a tool for evaluating and analyzing the mean switching time at a given value of current (smaller than the depairing critical current). The model indicates that although, in general, several phase-slip events are necessary to induce switching via a thermal runaway, there is indeed a regime of temperatures and currents in which a single event is sufficient. We carry out a detailed comparison of the results of the model with experimental measurements of the distribution of switching currents, and provide an explanation for the rather counterintuitive broadening of the distribution width that is observed upon lowering the temperature. Moreover, we identify a regime in which the experiments are probing individual phase-slip events, and thus offer a way of unearthing and exploring the physics of nanoscale quantum tunneling of the one-dimensional collective quantum field associated with the superconducting order parameter.
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 (up) ISBN Medium
Area Expedition Conference
Notes Recommended by Klapwijk Approved no
Call Number Serial 923
Permanent link to this record