74 results on '"Boris S. Karasik"'
Search Results
2. Tuning Y–Ba–Cu–O Focused Helium Ion Beam Josephson Junctions for Use as THz Mixers
- Author
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Shane A. Cybart, Daniel Cunnane, Hao Li, Anthony Cortez, Ethan Y. Cho, and Boris S. Karasik
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Superconductivity ,Spiral antenna ,Josephson effect ,Materials science ,Fabrication ,Ion beam ,business.industry ,Terahertz radiation ,chemistry.chemical_element ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,chemistry ,Condensed Matter::Superconductivity ,0103 physical sciences ,Optoelectronics ,Irradiation ,Electrical and Electronic Engineering ,010306 general physics ,business ,Helium - Abstract
We present Josephson junctions fabricated from high transition temperature superconductor YBa 2 Cu 3 O 7 coupled to spiral THz antennas. The fabrication process involves creating a Josephson junction at the center of a superconducting bridge embedded into a THz spiral antenna using irradiation from a focused helium ion beam. For low doses of helium irradiation, the junctions have metallic barriers and operate at temperatures as high as 67 K. For higher doses of irradiation, insulator barriers are created. These devices have higher resistance but require cooling to lower temperatures (~10 K) due to smaller critical currents. Through optimization of the dose and by trimming the width of the junctions, we have created high resistance devices to improve the impedance match to a spiral antenna. Under 90-GHz radiation, we observe up to 17 Shapiro steps in the I-V curve out to approximately 3 mV at a temperature of 10 K.
- Published
- 2019
3. Optimization of Parameters of MgB2Hot-Electron Bolometers
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Xiao Xing Xi, Matthäus A. Wolak, Boris S. Karasik, Narendra Acharya, Daniel Cunnane, and Jonathan H. Kawamura
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Spiral antenna ,Materials science ,Fabrication ,Hybrid physical-chemical vapor deposition ,Terahertz radiation ,business.industry ,Bolometer ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,Intermediate frequency ,Operating temperature ,law ,0103 physical sciences ,Optoelectronics ,Electrical and Electronic Engineering ,010306 general physics ,0210 nano-technology ,business ,Electrical impedance - Abstract
Hot-electron bolometers (HEBs) made with MgB 2 have proven to have a large intermediate frequency and have shown potential for a low noise into the terahertz range. Although practical results from these mixers have been achieved fairly quickly, effort is still needed to realize an MgB 2 HEB with improved sensitivity to compete with state-of-the-art mixers. Here, we present the results of our mixer work to achieve MgB 2 HEBs based on hybrid physical chemical vapor deposition grown films, with improved sensitivity and higher temperature operation. A new fabrication process is developed which utilizes even thinner films (
- Published
- 2017
4. As-Grown Versus Ion-Milled MgB2 Ultrathin Films for THz Sensor Applications
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Xiaoxing Xi, Boris S. Karasik, Matthäus A. Wolak, Daniel Cunnane, Narendra Acharya, and Thomas Melbourne
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Superconductivity ,Materials science ,Condensed matter physics ,business.industry ,Nanowire ,02 engineering and technology ,Chemical vapor deposition ,Conductivity ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Ion ,Carbon film ,0103 physical sciences ,Surface roughness ,Optoelectronics ,Electrical and Electronic Engineering ,Ion milling machine ,010306 general physics ,0210 nano-technology ,business - Abstract
The exploration of superconductivity in ultrathin films has attracted much attention in the past decades for device applications such as hot electron bolometers (HEBs) and superconducting nanowire single photon detectors (SNSPDs). With a superconducting critical temperature ( Tc ) of 39 K, which is far above that of other conventional Bardeen-Cooper-Schrieffer (BCS) superconductors, and its faster thermal response, ultrathin MgB 2 films present a promising alternative for the use in HEBs and SSNPDs. In this paper, we present the results on ultrathin MgB2 films grown by hybrid physical–chemical vapor deposition. The films less than 10 nm are difficult to achieve directly because of weak grain connectivity due to incomplete film coverage. To achieve high-quality films less than 10-nm Ar ion milling of thicker films was employed. The ultrathin films fabricated by ion milling show superior quality over as-grown films. The surface roughness of the films was significantly improved and the suppression of Tc from the bulk value is much slower in milled films than in as-grown films. The critical current density of the 5-nm milled film is 1 × 107 A·cm-2 at 4 K, which is the same as that of the 10-nm as-grown film.
- Published
- 2017
5. Far- and Mid-IR Heterodyne Detectors Based on MgB2
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Narendra Acharya, Wenura K. Withanage, Daniel Cunnane, Jonathan H. Kawamura, Boris S. Karasik, Xi Xiaoxing, and D. J. Hayton
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Physics ,Josephson effect ,Superconductivity ,High-temperature superconductivity ,Terahertz radiation ,business.industry ,Detector ,Bolometer ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Operating temperature ,Intermediate frequency ,law ,0103 physical sciences ,Optoelectronics ,010306 general physics ,0210 nano-technology ,business - Abstract
This will be an overview of our work on the development of hot-electron bolometers (HEB) and Josephson junctions (JJ) using thin films of high-TC MgB2 superconductor for applications as heterodyne detectors in the far-IR and mid-IR spectral ranges. Besides the high operating temperature (15–20 K), the MgB2 material provides a large intermediate frequency (IF) bandwidth $\sim 6$-7 GHz for HEB mixers and record high operating frequency $\sim 2$ THz for JJ mixers.
- Published
- 2019
6. Demonstration of a Frequency-Agile Quantum Well Based THz Heterodyne Detector
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Mark S. Sherwin, Jonathan H. Kawamura, Boris S. Karasik, Ken W. West, Mengchen Huang, Loren Pfeiffer, and Changyun Yoo
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Heterodyne ,Physics ,Physics::Instrumentation and Detectors ,business.industry ,Passive cooling ,Terahertz radiation ,Local oscillator ,Detector ,Bolometer ,Astrophysics::Instrumentation and Methods for Astrophysics ,Schottky diode ,Computer Science::Other ,law.invention ,Physics::Fluid Dynamics ,law ,Optoelectronics ,business ,Quantum well - Abstract
The field of THz mixers for astrophysics is dominated by superconducting hot-electron bolometers (HEBs), whereas Schottky-diode mixers have been the only devices suitable for planetary instruments. The Schottky mixers operate at ambient temperature, which is a great advantage for planetary applications, but are much less sensitive than the state-of-the art HEBs and require a 103 higher local oscillator (LO) power. Here, we have demonstrated a novel THz mixer which offers the best of both worlds: it operates at $\sim60\mathrm{K}$ (accessible by passive cooling on space), requires $\sim {\mu} \mathrm{W}$ LO power, and has a potential to be as sensitive as the HEB mixer.
- Published
- 2019
7. Demonstration of a tunable antenna-coupled intersubband terahertz (TACIT) mixer
- Author
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Boris S. Karasik, Mengchen Huang, Changyun Yoo, Ken W. West, Loren Pfeiffer, Jonathan H. Kawamura, and Mark S. Sherwin
- Subjects
010302 applied physics ,Physics - Instrumentation and Detectors ,Materials science ,Physics and Astronomy (miscellaneous) ,Terahertz radiation ,business.industry ,Bandwidth (signal processing) ,FOS: Physical sciences ,Heterojunction ,Instrumentation and Detectors (physics.ins-det) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Gate voltage ,01 natural sciences ,Frequency detection ,Intermediate frequency ,0103 physical sciences ,Optoelectronics ,0210 nano-technology ,Fermi gas ,business ,Quantum well - Abstract
A fast, voltage-tunable terahertz mixer based on the intersubband transition of a high-mobility 2-dimensional electron gas (2DEG) has been fabricated from a single 40 nm GaAs-AlGaAs square quantum well heterostructure. The device is called a Tunable Antenna-Coupled Intersubband Terahertz (TACIT) mixer, and shows tunability of the detection frequency from 2.52 THz to 3.11 THz with small (< 1 V) top gate and back gate voltage biases. Mixing at 2.52 THz has been observed at 60 K with a -3dB intermediate frequency (IF) bandwidth exceeding 6 GHz., 20 pages; 9 figures; the manuscript has been submitted for the Applied Physics Letters. This submission includes supplementary material
- Published
- 2020
8. Guest Editorial Introduction to the Mini-Special Issue on the 2018 IEEE 29th International Symposium on Space Terahertz Technology (ISSTT 2018)
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Boris S. Karasik and Imran Mehdi
- Subjects
Engineering ,Radiation ,business.industry ,Terahertz radiation ,Electrical engineering ,Electrical and Electronic Engineering ,Space (mathematics) ,business - Published
- 2018
9. Characterization of <tex-math notation='TeX'>$\hbox{MgB}_{2}$</tex-math> Superconducting Hot Electron Bolometers
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Teng Tan, Boris S. Karasik, Daniel Cunnane, Matthaeus Wolak, Narendra Acharya, Jonathan H. Kawamura, and Xiaoxing Xi
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Noise temperature ,Materials science ,business.industry ,Terahertz radiation ,Local oscillator ,Bolometer ,Condensed Matter Physics ,Noise (electronics) ,Electronic, Optical and Magnetic Materials ,law.invention ,Intermediate frequency ,Operating temperature ,law ,Bandwidth (computing) ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
Hot-Electron Bolometer (HEB) mixers have proven to be the best tool for high-resolution spectroscopy at the Terahertz frequencies. However, the current state of the art NbN mixers suffer from a small intermediate frequency (IF) bandwidth as well as a low operating temperature. MgB 2 is a promising material for HEB mixer technology in view of its high critical temperature and fast thermal relaxation allowing for a large IF bandwidth. In this work, we have fabricated and characterized thin-film (~15 nm) MgB 2 -based spiral antenna-coupled HEB mixers on SiC substrate. We achieved the IF bandwidth greater than 8 GHz at 25 K and the device noise temperature
- Published
- 2015
10. High-Operating-Temperature Superconducting Nanowire Single Photon Detectors based on Magnesium Diboride
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Daniel Cunnane, Ryan M. Briggs, Masataka Ohkubo, Boris S. Karasik, Hiroyuki Shibata, Masahiro Ukibe, Angel E. Velasco, Thomas Melbourne, Matthäus A. Wolak, Adriana E. Lita, Narendra Acharya, Xiaoxing Xi, Andrew D. Beyer, Varun B. Verma, Simone Frasca, Francesco Marsili, Matthew D. Shaw, and Nobuyuki Zen
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010302 applied physics ,Superconductivity ,Range (particle radiation) ,Materials science ,business.industry ,Nanowire ,Nanotechnology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Photon counting ,law.invention ,chemistry.chemical_compound ,chemistry ,Operating temperature ,law ,0103 physical sciences ,Magnesium diboride ,Optoelectronics ,Photolithography ,0210 nano-technology ,business ,Electron-beam lithography - Abstract
We report on optically sensitive 15 nm thick, 100 nm wide MgB 2 nanowires in the operating-temperature range 4–11 K.
- Published
- 2017
11. Graphene Microbolometers with Superconducting Contacts for Terahertz Photon Detection
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Heli Vora, Xu Du, Christopher B. McKitterick, Daniel E. Prober, and Boris S. Karasik
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Niobium nitride ,Terahertz radiation ,FOS: Physical sciences ,Physics::Optics ,02 engineering and technology ,01 natural sciences ,7. Clean energy ,Noise (electronics) ,law.invention ,chemistry.chemical_compound ,law ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,General Materials Science ,010306 general physics ,Ohmic contact ,Physics ,Superconductivity ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter::Other ,business.industry ,Graphene ,Bolometer ,Contact resistance ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,3. Good health ,chemistry ,Optoelectronics ,0210 nano-technology ,business - Abstract
We report on noise and thermal conductance measurements taken in order to determine an upper bound on the performance of graphene as a terahertz photon detector. The main mechanism for sensitive terahertz detection in graphene is bolometric heating of the electron system. To study the properties of a device using this mechanism to detect terahertz photons, we perform Johnson noise thermometry measurements on graphene samples. These measurements probe the electron-phonon behavior of graphene on silicon dioxide at low temperatures. Because the electron-phonon coupling is weak in graphene, superconducting contacts with large gap are used to confine the hot electrons and prevent their out-diffusion. We use niobium nitride leads with a $T_\mathrm{c}\approx 10$ K to contact the graphene. We find these leads make good ohmic contact with very low contact resistance. Our measurements find an electron-phonon thermal conductance that depends quadratically on temperature above 4 K and is compatible with single terahertz photon detection., Comment: 6 Pages, 4 Figures, Conference Proceedings from LTD-15
- Published
- 2014
12. THz Hot-Electron Micro-Bolometer Based on Low-Mobility 2-DEG in GaN Heterostructure
- Author
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Mehdi Pakmehr, Vladimir Mitin, Imran Mehdi, J. Gill, Ramaswamy Rahul, Andrei Sergeev, Boris S. Karasik, V. Pogrebnyak, Jae Kyu Choi, Michael Shur, and A. Muravjov
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Materials science ,business.industry ,Terahertz radiation ,Bolometer ,Contact resistance ,Wide-bandgap semiconductor ,Impedance matching ,Heterojunction ,law.invention ,Responsivity ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Instrumentation ,Noise-equivalent power - Abstract
We present the results on design, fabrication, and characterization of a hot-electron bolometer based on low-mobility 2-D electron gas (2-DEG) in an AlGaN/GaN heterostructure. The characterization of our hot-electron bolometers demonstrates that the following can be achieved simultaneously: 1) strong coupling to incident THz radiation due to strong Drude absorption; 2) significant THz heating of 2-DEG due to the small value of the electron heat capacity; and 3) high responsivity due to the strong temperature dependence of 2-DEG resistance. Low contact resistance achieved in our devices ensures that THz radiation couples primarily to the 2-DEG. Due to a small electron momentum relaxation time, the real part of the 2-DEG sensor impedance is ~50-100 Ω, which provides good impedance matching between sensors and antennas. The room temperature responsivity of our devices reaches ~0.04 A/W at 2.55 THz along with a noise equivalent power of ~5 nW/Hz1/2.
- Published
- 2013
13. High-Operating-Temperature Superconducting Nanowire Single Photon Detectors
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Angel E. Velasco, Daniel Cunnane, Xiaoxing Xi, Andrew D. Beyer, Ryan M. Briggs, Narendra Acharya, Boris S. Karasik, Matthäus A. Wolak, Matthew D. Shaw, and Francesco Marsili
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Superconductivity ,Range (particle radiation) ,Materials science ,business.industry ,Photon detector ,Nanowire ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Wavelength ,Operating temperature ,0103 physical sciences ,Optoelectronics ,010306 general physics ,0210 nano-technology ,business ,Sensitivity (electronics) - Abstract
We report on 5 nm thick, 100 nm wide MgB 2 nanowires with single-photon sensitivity at 635 nm wavelength in the operating-temperature range 3–10 K.
- Published
- 2016
14. Photon Number-Resolved Detection With Sequentially Connected Nanowires
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A. Verevkin, Vladimir Mitin, Andrei Antipov, Matthew Bell, Andrei Sergeev, and Boris S. Karasik
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Physics ,Resistive touchscreen ,Photon ,Physics::Instrumentation and Detectors ,business.industry ,Amplifier ,Detector ,Nanowire ,Impedance matching ,Physics::Optics ,Photodetector ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,Optics ,Condensed Matter::Superconductivity ,Electrical and Electronic Engineering ,Photonics ,business - Abstract
Sequentially connected superconducting nanowires, such as nanopatterned meanders, are very promising candidates for single-photon detectors capable to resolve a number of photons in the pulse. In such devices, the photon number-resolved (PNR) mode is possible due to independent detection of electromagnetic quanta by different regions of the meander. Every photon creates a resistive region in the superconductive meander and the total resistance is expected to be proportional to the number of photons absorbed. While the PNR mode can be realized with available single-photon detectors based on NbN nanowires, up to now it has not been observed experimentally. Here we show that the PNR mode in NbN requires the proper impedance matching between readout circuitry and nanowire-based detector. We discuss possible design of the readout circuitry for PNR detection. Results of modeling show that a high impedance amplifier placed in close proximity to the superconducting nanostructure can provide effective readout for the NbN nanowire-based detector operating in PNR mode.
- Published
- 2007
15. Record-Low NEP in Hot-Electron Titanium Nanobolometers
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David Olaya, Jian Wei, Jonathan H. Kawamura, Andrei Sergeev, Sergei V. Pereverzev, Boris S. Karasik, Michael Gershenson, and William R. McGrath
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Physics ,Condensed matter physics ,Phonon ,business.industry ,Bolometer ,Niobium ,chemistry.chemical_element ,Condensed Matter Physics ,Thermal conduction ,Particle detector ,Electronic, Optical and Magnetic Materials ,law.invention ,Wavelength ,chemistry ,law ,Optoelectronics ,Electrical and Electronic Engineering ,Spectroscopy ,business ,Noise (radio) - Abstract
We are developing hot-electron superconducting transition-edge sensors (TES) capable of counting THz photons and operating at . We fabricated superconducting Ti nanosensors with Nb contacts with a volume of on planar Si substrates and have measured the thermal conductance in the material, G=4times10-3 W/K at 0.3 K, caused predominantly by the weak electron-phonon coupling. The corresponding phonon-noise NEP=3times10-19 W/Hz1/2 . Detection of single optical photons (1550 nm and 670 nm wavelength) has been demonstrated for larger devices and yielded the thermal time constants of 30 mus at 145 mK and of 25 mus at 190 mK. This hot-electron direct detector (HEDD) is expected to have a small enough energy fluctuation noise for detecting individual photons with v>THz where NEP~3times10-20 W/Hz1/2 is needed for spectroscopy in space.
- Published
- 2007
16. High-TC THz HEB mixers: Progress and prospects
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Daniel Cunnane, Andrei Sergeev, and Boris S. Karasik
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Superconductivity ,Electron density ,Materials science ,Terahertz radiation ,business.industry ,Bandwidth (signal processing) ,Bolometer ,law.invention ,Intermediate frequency ,law ,Optoelectronics ,Thermal model ,Thin film ,business - Abstract
We analyze the pathways for achieving the THz hot-electron bolometer (HEB) mixers using high-T C superconductors. Requirements to the material in order to obtain large (up to 10 GHz) intermediate frequency bandwidth as well as recent results on MgB 2 HEB mixer devices are discussed. Based on a thermal model of the energy relaxation in a thin film, we explain the difference between the mixing behaviors in previously studied HEB materials. We also introduce the concept of the HEB mixer based on the low electron density MBE-grown quasi-2DEG LaCuO/LaSrCuO superconductors with tunable critical temperature.
- Published
- 2015
17. Superconducting Nanowire Detectors Based on MgB2
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Daniel Cunnane, Francesco Marsili, Boris S. Karasik, Andrew D. Beyer, Matthaeus Wolak, Narendra Acharya, Ryan M. Briggs, Xiaoxing Xi, and Matthew D. Shaw
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Superconductivity ,Photon ,Materials science ,business.industry ,Scanning electron microscope ,Nanowire ,Optoelectronics ,Thin film ,Photonics ,business ,Absorption (electromagnetic radiation) ,Electron-beam lithography - Abstract
We fabricated and characterized the optical response of MgB 2 nanowires with critical temperature T C = 33 K. The devices showed optical response at 4 K and sub-nanosecond relaxation time. The detectors responded to the simultaneous absorption of three photons, but not to single photons.
- Published
- 2015
18. THz Hot-Electron Photon Counter
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Andrei Sergeev and Boris S. Karasik
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Physics ,Photon ,business.industry ,Terahertz radiation ,Dynamic range ,Bolometer ,Time constant ,Condensed Matter Physics ,Photon counting ,Particle detector ,Electronic, Optical and Magnetic Materials ,law.invention ,Calorimeter ,Optics ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
We discuss an implementation of a hot-electron transition-edge sensor (TES) capable of counting THz photons. The main need for such a THz calorimeter is spectroscopy on future space telescopes with a background limited NEP/spl sim/10/sup -20/ W/Hz/sup 1/2/. The micromachined bolometers will unlikely reach such sensitivity at temperatures above 10 mK. The hot-electron TES with sufficient sensitivity will still have a time constant /spl sim/0.1-1.0 ms that is too short for integrating a flux of THz background photons arriving at a rate of
- Published
- 2005
19. Development of hot-electron THz bolometric mixers using MgB2thin films
- Author
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Boris S. Karasik, J. Kawamura, Xiaoxing Xi, Matthaeus Wolak, and Daniel Cunnane
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Heterodyne ,Materials science ,Optics ,Intermediate frequency ,Terahertz radiation ,business.industry ,Local oscillator ,Optoelectronics ,Thin film ,Ion milling machine ,Sputter deposition ,business ,Microwave - Abstract
Terahertz high-resolution spectroscopy of interstellar molecular clouds greatly relies on hot-electron superconducting bolometric (HEB) mixers. Current state-of-the-art receivers use mixer devices made from ultrathin (~ 3-5 nm) films of NbN with critical temperature ~ 9-11 K. Such mixers have been deployed on a number of groundbased, suborbital, and orbital platforms including the HIFI instrument on the Hershel Space Observatory. Despite its good sensitivity and well-established fabrication process, the NbN HEB mixer suffers from the narrow intermediate frequency (IF) bandwidth ~ 2-3 GHz and is limited to operation at liquid Helium temperature. As the heterodyne receivers are now trending towards “high THz” frequencies, the need in a larger IF bandwidth becomes more pressing since the same velocity resolution for a Doppler shifted line at 5 THz requires a 5-times greater IF bandwidth than at 1 THz. Our work is focusing on the realization of practical HEB mixers using ultrathin (10-20 nm) MgB 2 films. They are prepared using a Hybrid Physical-Chemical Vapor Deposition (HPCVD) process yielding ultrathin films with critical temperature ~ 37-39 K. The expectation is that the combination of small thickness, high acoustic phonon transparency at the interface with the substrate, and very short electron-phonon relaxation time may lead to IF bandwidth ~ 10 GHz or even higher. SiC continues to be the most favorable substrate for MgB 2 growth and as a result, a study has been conducted on the transparency of SiC at THz frequencies. FTIR measurements show that semi-insulating SiC substrates are at least as transparent as Si up to 2.5 THz. Currently films are passivated using a thin (10 nm) SiO2 layer which is deposited ex-situ via RF magnetron sputtering. Micron-sized spiral antenna-coupled HEB mixers have been fabricated using MgB2 films as thin as 10 nm. Fabrication was done using contact UV lithography and Ar Ion milling, with E-beam evaporated Au films deposited for the antenna. Measurements have been carried out on these devices in the DC, Microwave, and THz regimes. The devices are capable of mixing signals above 20 K indicating that operation may be possible using a cryogen-free cooling system. We will report the results of all measurements taken to indicate the local oscillator power requirements and the IF bandwidth of MgB 2 HEB mixers.
- Published
- 2014
20. Prospective performance of graphene HEB for ultrasensitive detection of sub-mm radiation
- Author
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Boris S. Karasik, Daniel E. Prober, and Christopher B. McKitterick
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Materials science ,Physics - Instrumentation and Detectors ,FOS: Physical sciences ,02 engineering and technology ,Radiation ,7. Clean energy ,01 natural sciences ,law.invention ,Operating temperature ,law ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,General Materials Science ,010306 general physics ,Noise-equivalent power ,Coupling ,Condensed Matter - Mesoscale and Nanoscale Physics ,business.industry ,Graphene ,Detector ,Bolometer ,Johnson–Nyquist noise ,Instrumentation and Detectors (physics.ins-det) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Optoelectronics ,0210 nano-technology ,business - Abstract
Noise Equivalent Power and time constant of a submillimeter wave Hot-Electron Bolometer (HEB) made from monolayer graphene are analyzed using the lowest electron-phonon thermal conductance data reported to date. Frequency-domain multiplexed Johnson Noise Thermometry (JNT) is used for the detector readout. Planar microantennas or waveguides can provide efficient coupling of the graphene microdevice to radiation. The results show that the graphene HEB detector can be radiation background limited at very low level corresponding to the photon noise on a space telescope with cryogenically cooled mirror. Beside the high sensitivity, absence of a hard power saturation limit, higher operating temperature, and the ability to read 1000s of elements with a single broadband amplifier will be the advantages of such a detector., 7 page, 1 figure, 15th International Workshop on Low Temperature Detectors (Pasadena, California, June 24-28, 2013)
- Published
- 2014
21. Normal Metal Hot-Electron Nanobolometer with Johnson Noise Thermometry Readout
- Author
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Christopher B. McKitterick, Boris S. Karasik, Theodore Reck, and Daniel E. Prober
- Subjects
Superconductivity ,Physics ,Radiation ,Physics - Instrumentation and Detectors ,Condensed Matter - Mesoscale and Nanoscale Physics ,business.industry ,Terahertz radiation ,Amplifier ,Niobium ,chemistry.chemical_element ,FOS: Physical sciences ,Johnson–Nyquist noise ,Instrumentation and Detectors (physics.ins-det) ,Bismuth ,chemistry ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Optoelectronics ,Electrical and Electronic Engineering ,Photonics ,business ,Astrophysics - Instrumentation and Methods for Astrophysics ,Noise-equivalent power ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
The sensitivity of a THz hot-electron nanobolometer (nano-HEB) made from a normal metal is analyzed. Johnson Noise Thermometry (JNT) is employed as a readout technique. In contrast to its superconducting TES counterpart, the normal-metal nano-HEB can operate at any cryogenic temperature depending on the required radiation background limited Noise Equivalent Power (NEP). It does not require bias lines; 100s of nano-HEBs can be read by a single low-noise X-band amplifier via a filter bank channelizer. The modeling predicts that even with the sensitivity penalty due to the amplifier noise, an NEP ~ 10$^{-20}$ - 10$^{-19}$ W/Hz$^{1/2}$ can be expected at 50-100 mK in 10-20 nm thin titanium (Ti) normal metal HEBs with niobium (Nb) contacts. This NEP is fairly constant over a range of readout frequencies ~ 10 GHz. Although materials with weaker electron-phonon coupling (bismuth, graphene) do not improve the minimum achievable NEP, they can be considered if a larger than 10 GHz readout bandwidth is required., Comment: 5 pages, 5 figures, presented at the 25th International Symposium on Space Terahertz Technology (Moscow, Russia, 27-30 April 2014)
- Published
- 2014
- Full Text
- View/download PDF
22. Monolayer graphene bolometer as a sensitive far-IR detector
- Author
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Christopher B. McKitterick, Boris S. Karasik, and Daniel E. Prober
- Subjects
Condensed Matter - Materials Science ,Physics - Instrumentation and Detectors ,Materials science ,Condensed Matter - Mesoscale and Nanoscale Physics ,business.industry ,Amplifier ,Bolometer ,Astrophysics::Instrumentation and Methods for Astrophysics ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Operational amplifier applications ,Johnson–Nyquist noise ,Instrumentation and Detectors (physics.ins-det) ,Noise (electronics) ,law.invention ,Narrowband ,law ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Optoelectronics ,Astrophysics - Instrumentation and Methods for Astrophysics ,business ,Waveguide ,Noise-equivalent power ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
In this paper we give a detailed analysis of the expected sensitivity and operating conditions in the power detection mode of a hot-electron bolometer (HEB) made from a few {\mu}m$^2$ of monolayer graphene (MLG) flake which can be embedded into either a planar antenna or waveguide circuit via NbN (or NbTiN) superconducting contacts with critical temperature ~ 14 K. Recent data on the strength of the electron-phonon coupling are used in the present analysis and the contribution of the readout noise to the Noise Equivalent Power (NEP) is explicitly computed. The readout scheme utilizes Johnson Noise Thermometry (JNT) allowing for Frequency-Domain Multiplexing (FDM) using narrowband filter coupling of the HEBs. In general, the filter bandwidth and the summing amplifier noise have a significant effect on the overall system sensitivity. The analysis shows that the readout contribution can be reduced to that of the bolometer phonon noise if the detector device is operated at 0.05 K and the JNT signal is read at about 10 GHz where the Johnson noise emitted in equilibrium is substantially reduced. Beside the high sensitivity (NEP < 10$^{-20}$ W/Hz$^{1/2}$, this bolometer does not have any hard saturation limit and thus can be used for far-IR sky imaging with arbitrary contrast. By changing the operating temperature of the bolometer the sensitivity can be fine tuned to accommodate the background photon flux in a particular application. By using a broadband low-noise kinetic inductance parametric amplifier, ~100s of graphene HEBs can be read simultaneously without saturation of the system output., Comment: 9 pages. 6 figure, SPIE Astronomical Telescopes + Instrumentation, Montr\'eal, Quebec, Canada, 22-27 June, 2014
- Published
- 2014
- Full Text
- View/download PDF
23. Noise and conversion efficiency of aluminum superconducting hot-electron bolometer mixer
- Author
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William R. McGrath, Anders Skalare, Boris S. Karasik, P. M. Echternach, A. Verevkin, Daniel E. Prober, Henry G. LeDuc, and I. Siddiqi
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Physics ,Superconductivity ,Noise temperature ,business.industry ,Terahertz radiation ,Local oscillator ,Bolometer ,Energy conversion efficiency ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Intermediate frequency ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Microwave - Abstract
We report on microwave measurements of superconducting aluminum hot-electron bolometers (Al HEBs). Diffusion-cooled Al HEB mixers are good candidates for space-borne applications in the Terahertz frequency range since they are predicted to have small local oscillator (LO) power requirements, intermediate frequency (IF) bandwidths /spl gsim/10 GHz, and a noise temperature lower than that of Nb and NbN HEB mixers. Mixer measurements were made at an LO frequency /spl sim/30 GHz, with an IF in the range 0.1 to 7.3 GHz. For T
- Published
- 2001
24. Fabrication of terahertz YBa/sub 2/Cu/sub 3/O/sub 7-δ/ hot-electron bolometer mixers
- Author
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J.B. Barner, William R. McGrath, A.W. Kleinsasser, M. J. Burns, and Boris S. Karasik
- Subjects
Heterodyne ,Superconductivity ,Fabrication ,High-temperature superconductivity ,Materials science ,Band gap ,business.industry ,Terahertz radiation ,Bolometer ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Optoelectronics ,Heterodyne detection ,Electrical and Electronic Engineering ,business - Abstract
Superconducting hot-electron bolometer (HEB) mixers are promising heterodyne detectors for THz frequencies. HEB mixers operating at 4 K or below offer the possibility of near-quantum-limited performance without an upper frequency limit imposed by the superconducting energy gap. High temperature superconductor HEB mixers offer very sensitive, low power heterodyne detectors operating at temperatures approaching 90 K for applications requiring closed-cycle refrigeration. We report on recent progress in fabricating and characterizing high-T/sub c/ mixers based on ultra-thin (10-20 nm) YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// films patterned to submicrometer dimensions (0.1-1 /spl mu/m) and incorporated into 1-3 THz planar mixer circuits.
- Published
- 1999
25. Optimal choice of material for HEB superconducting mixers
- Author
-
William R. McGrath, R. A. Wyss, and Boris S. Karasik
- Subjects
Superconductivity ,Materials science ,Condensed matter physics ,business.industry ,Terahertz radiation ,Local oscillator ,Transition temperature ,Bandwidth (signal processing) ,Bolometer ,Electron ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Intermediate frequency ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
We demonstrate that a potential distinction in ultimate performance of phonon-cooled and diffusion-cooled HEB mixers is not due to the cooling mechanisms but rather due to the different properties of available superconductors. The only available material for a phonon-cooled mixer with sufficiently large IF bandwidth (/spl sim/4 GHz) is NbN, whereas a variety of clean materials (e.g., Nb, NbC, Al) are suitable for a diffusion-cooled mixer. For a readily achievable device length of 0.1 /spl mu/m for example, the diffusion-cooled IF bandwidth can be /spl ges/10 GHz. The requirement of low local oscillator (LO) power can also be more easily met in diffusion-cooled devices by selection of a material with lower critical temperature and low density of electron states. In contrast, the parameters in the NbN-based mixer cannot be widely varied because of the high resistivity and high transition temperature of the material and the necessity of using ultrathin films. Given the limited availability of LO power from compact solid-state sources at frequencies above 1 THz a diffusion-cooled mixer based on aluminum is a very attractive choice for low-background radioastronomy applications.
- Published
- 1999
26. [Untitled]
- Author
-
William R. McGrath and Boris S. Karasik
- Subjects
Physics ,Radiation ,business.industry ,Bolometer ,Bandwidth (signal processing) ,Microwave transmission ,Condensed Matter Physics ,law.invention ,Optics ,law ,Scattering parameters ,Calibration ,Wave transmission ,Electrical and Electronic Engineering ,business ,Instrumentation ,Electrical impedance ,Microwave - Abstract
The impedance of the supconducting hot-electron bolometer mixer was measured in the range 0.2-4 GHz. A special technique relying on determination of S21 transmission parameter of the device was used. Many advantages of the techinque (wide frequency range, in sity calibration, low tes power, accuracy) are demonstrated. The estimate of the mixer bandwidth from the impedance data using the mixer theory is in good agreement with the results ofthe direct bandwidth measurements.
- Published
- 1999
27. A low-noise 2.5 THz superconductive Nb hot-electron mixer
- Author
-
Henry G. LeDuc, William R. McGrath, Boris S. Karasik, Michael C. Gaidis, and B. Bumble
- Subjects
Physics ,Noise temperature ,Sideband ,business.industry ,Terahertz radiation ,Local oscillator ,Far-infrared laser ,Bolometer ,Superheterodyne receiver ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Electron cooling - Abstract
We report on the development of a quasioptical Nb hot-electron bolometer mixer for a 2.5 THz heterodyne receiver. The devices are fabricated from a 12 nm thick Nb film, and have a 0.30 /spl mu/m/spl times/0.15 /spl mu/m in-plane size, thus exploiting diffusion as the electron cooling mechanism. The rf coupling was provided by a twin-slot planar antenna on an elliptical Si lens. A specially designed 2.5 THz system, using a CO/sub 2/-pumped FIR laser as local oscillator (LO), with rf hot/cold loads enclosed in vacuum to avoid atmospheric absorption, was used in the experiment. The experimentally measured double sideband (DSB) noise temperature of the receiver was as low as /spl les/3000 K, with an estimated mixer noise temperature of /spl ap/750 K. These results demonstrate the operation of the diffusion-cooled bolometer mixer above 2 THz.
- Published
- 1997
28. Fabrication of high-T/sub c/ hot-electron bolometric mixers for terahertz applications
- Author
-
A.W. Kleinsasser, Boris S. Karasik, Richard P. Vasquez, K. A. Delin, Michael C. Gaidis, M. J. Burns, and William R. McGrath
- Subjects
Superconductivity ,Heterodyne ,High-temperature superconductivity ,Materials science ,Fabrication ,business.industry ,Terahertz radiation ,Bolometer ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Micrometre ,Planar ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
Superconducting hot-electron bolometers (HEB) represent a promising candidate for heterodyne mixing at frequencies exceeding 1 THz. Nb HEB mixers offer performance competitive with tunnel junctions without the frequency limit imposed by the superconducting energy gap. Although the performance of YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// HEB mixers is not projected to be superior to that of Nb devices, which operate at low temperatures, they introduce the possibility of sensitive, low power heterodyne detectors operating at temperatures approaching 90 K for applications requiring portability and closed-cycle refrigeration. We report on the fabrication and characterization, both DC and RF, of high-T/sub c/ mixers based on ultra-thin (/spl les/20 nm) YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// films patterned to micrometer dimensions and incorporated into 2.5 THz planar mixer circuits.
- Published
- 1997
29. Noise bandwidth of diffusion-cooled hot-electron bolometers
- Author
-
Peter Burke, William R. McGrath, Michael C. Gaidis, Boris S. Karasik, Robert Schoelkopf, Henry G. LeDuc, Anders Skalare, Daniel E. Prober, and B. Bumble
- Subjects
Physics ,Noise temperature ,business.industry ,Noise spectral density ,Y-factor ,Condensed Matter Physics ,Noise figure ,Noise (electronics) ,Electronic, Optical and Magnetic Materials ,Noise generator ,Optoelectronics ,Effective input noise temperature ,Flicker noise ,Electrical and Electronic Engineering ,business - Abstract
We present studies of the input and output noise of diffusion cooled hot-electron bolometer mixers. By simultaneously measuring the gain and noise (with a 14 GHz LO) as a function of intermediate frequency for a 0.16 /spl mu/m diffusion cooled Nb device, we show that the noise bandwidth (4 GHz) is larger than the gain bandwidth (2.4 GHz). The output noise is 55 K, and the mixer noise is very low, 340 K DSB. This shows that diffusion cooled devices have low noise over a broad enough intermediate frequency band for practical applications in THz receivers.
- Published
- 1997
30. Analysis of a high-Tchot-electron superconducting mixer for terahertz applications
- Author
-
Michael C. Gaidis, Boris S. Karasik, and William R. McGrath
- Subjects
Superconductivity ,High-temperature superconductivity ,Materials science ,Infrared ,business.industry ,Terahertz radiation ,Superheterodyne receiver ,Bolometer ,Analytical chemistry ,General Physics and Astronomy ,law.invention ,Thermal conductivity ,law ,Optoelectronics ,business ,Frequency mixer - Abstract
The prospects of a YBa2Cu3O7(delta)(YBCO) hot-electron bolometer (HEB) mixer for a THz heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate.
- Published
- 1997
31. Quasioptical superconducting hot electron bolometer for submillmeter waves
- Author
-
Yu. P. Gousev, Karl Friedrich Renk, E. M. Gershenzon, Boris S. Karasik, A.D. Semenov, R. S. Nebosis, H. S. Barowski, and G.N. Gol'tsman
- Subjects
Physics ,Superconductivity ,Radiation ,Terahertz radiation ,business.industry ,Bolometer ,Time constant ,Condensed Matter Physics ,Directivity ,law.invention ,Optics ,law ,Electrical and Electronic Engineering ,Antenna (radio) ,business ,Instrumentation ,Noise-equivalent power - Abstract
We report on a superconducting hot electron bolometer coupled to radiation via a broadband antenna. The bolometer, a structured NbN film, was patterned on a thin dielectric membrane between terminals of a gold slotline antenna. We investigated the response to submillimeter radiation (wave-lengths ∼ 0.1 mm to 0.7 mm) in the fundamental Gaussian mode. We found that the directivity of the antenna was constant within a factor of 2.5 through the whole experimental range. The noise equivalent power of the bolometer at 119 µm was ∼ 3 · 10−13 W/Hz1/2; a time constant of ∼ 160 ps was estimated.
- Published
- 1996
32. Low-noise THz MgB2 Josephson mixer
- Author
-
Matthäus A. Wolak, Boris S. Karasik, Narendra Acharya, Daniel Cunnane, Jonathan H. Kawamura, and Xiaoxing Xi
- Subjects
Josephson effect ,Spiral antenna ,Materials science ,Physics and Astronomy (miscellaneous) ,Terahertz radiation ,business.industry ,Detector ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Pi Josephson junction ,Lens (optics) ,Planar ,law ,0103 physical sciences ,Optoelectronics ,Heterodyne detection ,010306 general physics ,0210 nano-technology ,business - Abstract
The potential applications for high frequency operation of the Josephson effect in MgB2 include THz mixers, direct detectors, and digital circuits. Here we report on MgB2 weak links which exhibit the Josephson behavior up to almost 2 THz and using them for low-noise heterodyne detection of THz radiation. The devices are made from epitaxial film grown in the c-axis direction by the hybrid physical-chemical vapor deposition method. The current in the junctions travels parallel to the surface of the film, thus making possible a large contribution of the quasi-two-dimensional σ-gap in transport across the weak link. These devices are connected to a planar spiral antenna with a dielectric substrate lens to facilitate coupling to free-space radiation for use as a detector. The IcRn product of the junction is 5.25 mV, giving confirmation of a large gap parameter. The sensitivity of the mixer was measured from 0.6 THz to 1.9 THz. At a bath temperature of over 20 K, a mixer noise temperature less than 2000 K (DSB)...
- Published
- 2016
33. MgB2 ultrathin films fabricated by hybrid physical chemical vapor deposition and ion milling
- Author
-
Narendra Acharya, Mitra L. Taheri, Xiaoxing Xi, Nam Hoon Lee, Boris S. Karasik, Daniel Cunnane, Andrew C. Lang, Teng Tan, and Matthäus A. Wolak
- Subjects
Superconductivity ,Phase transition ,Materials science ,Hybrid physical-chemical vapor deposition ,Condensed matter physics ,business.industry ,Phonon ,lcsh:Biotechnology ,General Engineering ,02 engineering and technology ,Chemical vapor deposition ,021001 nanoscience & nanotechnology ,01 natural sciences ,lcsh:QC1-999 ,Carbide ,lcsh:TP248.13-248.65 ,0103 physical sciences ,Optoelectronics ,General Materials Science ,Ion milling machine ,Thin film ,010306 general physics ,0210 nano-technology ,business ,lcsh:Physics - Abstract
In this letter, we report on the structural and transport measurements of ultrathin MgB2 films grown by hybrid physical-chemical vapor deposition followed by low incident angle Ar ion milling. The ultrathin films as thin as 1.8 nm, or 6 unit cells, exhibit excellent superconducting properties such as high critical temperature (Tc) and high critical current density (Jc). The results show the great potential of these ultrathin films for superconducting devices and present a possibility to explore superconductivity in MgB2 at the 2D limit.
- Published
- 2016
34. Hot electron quasioptical NbN superconducting mixer
- Author
-
H. Ekstrom, E. L. Kollberg, K. S. Yngvesson, S.I. Svechnikov, Boris M. Voronov, Stellan Jacobsson, Boris S. Karasik, G.N. Gol'tsman, and E. M. Gershenzon
- Subjects
Superconductivity ,Materials science ,business.industry ,Bolometer ,STRIPS ,Electron ,Atmospheric temperature range ,Radiation ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Intermediate frequency ,Operating temperature ,law ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
Hot electron superconductor mixer devices made of thin NbN films on SiO/sub 2/-Si/sub 3/N/sub 4/-Si membrane have been fabricated for 300-350 GHz operation. The device consists of 5-10 parallel strips each 5 /spl mu/m long by 1 /spl mu/m wide which are coupled to a tapered slot-line antenna. The I-V characteristics and position of optimum bias point were studied in the temperature range 4.5-8 K. The performance of the mixer at higher temperatures is closer to that predicted by theory for uniform electron heating. The intermediate frequency bandwidth versus bias has also been investigated. At the operating temperature 4.2 K a bandwidth as wide as 0.8 GHz has been measured for a mixer made of 6 nm thick film. The bandwidth tends to increase with operating temperature. The performance of the NbN mixer is expected to be better for higher frequencies where the absorption of radiation should be more uniform. >
- Published
- 1995
35. NbN hot electron superconducting mixers for 100 GHz operation
- Author
-
S. Jacobsson, E. L. Kollberg, O. Okunev, H. Ekstrom, G.N. Gol'tsman, A. Dzardanov, Boris S. Karasik, and E. M. Gershenzon
- Subjects
Physics ,Superconductivity ,Noise temperature ,business.industry ,Superconducting material ,Local oscillator ,Bandwidth (signal processing) ,Superconducting magnetic energy storage ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Type-II superconductor ,Hot electron - Abstract
NbN is a promising superconducting material for hot-electron superconducting mixers with an IF bandwidth larger than 1 GHz. In the 1OO GHz frequency range, the following parameters were obtained for 50 /spl Aring/ thick NbN films at 4.2 K: receiver noise temperature (DSB) /spl sim/1000 K; conversion loss /spl sim/10 dB; IF bandwidth /spl sim/1 GHz; and local oscillator power /spl sim/1 /spl mu/W. An increase of the critical current of the NbN film, increased working temperature, and a better mixer matching may allow a broader IF bandwidth up to 2 GHz, reduced conversion losses down to 3-5 dB and a receiver noise temperature (DSB) down to 200-300 K. >
- Published
- 1995
36. Optical mixing in thin YBa/sub 2/Cu/sub 3/O/sub 7-x/ films
- Author
-
A.I. Elantev, Boris S. Karasik, M. Danerud, E. M. Gershenzon, G.N. Gol'tsman, Mikael Lindgren, Dag Winkler, and M. A. Zorin
- Subjects
Superconductivity ,Resistive touchscreen ,High-temperature superconductivity ,Materials science ,business.industry ,Bolometer ,Condensed Matter Physics ,Epitaxy ,Electronic, Optical and Magnetic Materials ,Semiconductor laser theory ,law.invention ,Wavelength ,law ,Modulation ,Optoelectronics ,Electrical and Electronic Engineering ,business - Abstract
High quality, j/sub c/ (77 K)>10/sup 6/ A/cm/sup 2/, epitaxial YBa/sub 2/Cu/sub 3/O/sub 7-x/ films of 50 nm thickness were patterned into ten parallel 1 /spl mu/m wide strips. The film structure was coupled to a single-mode fiber. Mixer response was obtained at 0.78 /spl mu/m using laser frequency modulation and an optical delay line. Using two semiconductor lasers at 1.55 /spl mu/m wavelength the beating signal was used to measure the photoresponse up to 18 GHz. Nonequilibrium photoresponse in the resistive state of the superconductor was observed. Bolometric response dominates up to 3 GHz, after which the nonequilibrium response is constant up to the frequency limit of our registration system. Using an electron heating model the influence of different thermal processes on the conversion loss has been analyzed. Ways of increasing the sensitivity are also discussed. >
- Published
- 1995
37. Subnanosecond switching of YBaCuO films between superconducting and normal states induced by current pulse
- Author
-
A. I. Elant'ev, E. M. Gershenzon, I. I. Milostnaya, M. A. Zorin, Boris S. Karasik, and G.N. Gol'tsman
- Subjects
Superconductivity ,Resistive touchscreen ,Laser ablation ,Materials science ,business.industry ,Phonon ,Analytical chemistry ,General Physics and Astronomy ,Substrate (electronics) ,Picosecond ,Optoelectronics ,Electron temperature ,business ,Voltage - Abstract
A study is reported of the current switching in high‐quality YBaCuO films deposited onto NdGaO3 and ZrO2 substrates between superconducting (S) and normal (N) states. The films 60–120 nm thick prepared by laser ablation were structured into single strips between gold contacts. The time dependence of the resistance after application of the voltage step to the film was monitored. Experiment performed within certain ranges of voltage amplitudes and temperatures has shown the occurrence of the fast stage (shorter than 400 ps) both in S‐N and N‐S transitions. A fraction of the film resistance changing within this stage in the S‐N transition increases with the current amplitude. A subnanosecond N‐S stage becomes more pronounced for shorter pulses. The fast switching is followed by the much slower change of resistance. The mechanism of switching is discussed in terms of the hot‐electron phenomena in YBaCuO. The contributions of other thermal processes (e.g., a phonon escape from the film, a heat diffusion in the film and substrate, a resistive domain formation) in the subsequent stage of the resistance dynamic have been also discussed. The basic limiting characteristics (average dissipated power, energy needed for switching, maximum repetition rate) of a picosecond switch which is proposed to be developed are estimated.
- Published
- 1995
38. Conversion gain and noise of niobium superconducting hot-electron-mixers
- Author
-
E. L. Kollberg, Boris S. Karasik, K. S. Yngvesson, and H. Ekstrom
- Subjects
Heterodyne ,Physics ,Noise temperature ,Resistive touchscreen ,Radiation ,Noise measurement ,business.industry ,Niobium ,chemistry.chemical_element ,STRIPS ,Condensed Matter Physics ,law.invention ,chemistry ,Intermediate frequency ,law ,Electronic engineering ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Microwave - Abstract
A study has been done of microwave mixing at 20 GHz using the nonlinear (power dependent) resistance of thin niobium strips in the resistive state. Our experiments give evidence that electron-heating is the main cause of the nonlinear phenomenon. Also a detailed phenomenological theory for the determination of conversion properties is presented. This theory is capable of predicting the frequency-conversion loss rather accurately for arbitrary bias by examining the I-V characteristic, Knowing the electron temperature relaxation time, and using parameters derived from the I-V-characteristic also allows us to predict the -3-dB IF bandwidth. Experimental results are in excellent agreement with the theoretical predictions. The requirements on the mode of operation and on the film parameters for minimizing the conversion loss (and even achieving conversion gain) are discussed in some detail. Our measurements demonstrate an intrinsic conversion loss as low as 1 dB. The maximum IF frequency defined for 3-dB drop in conversion gain, is about 80 MHz. Noise measurements indicate a device output noise temperature of about 50 K and SSB mixer noise temperature below 250 K. This type of mixer is considered very promising for use in low-noise heterodyne receivers at THz frequencies. >
- Published
- 1995
39. Nonequilibrium and bolometric responses of YBaCuO thin films to high-frequency modulated laser radiation
- Author
-
M. Danerud, Dag Winkler, E. M. Gershenzon, M. A. Zorin, Gregory Goltsman, Mikael Lindgren, and Boris S. Karasik
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Phonon ,Bolometer ,Relaxation (NMR) ,Substrate (electronics) ,Condensed Matter Physics ,Laser ,Electronic, Optical and Magnetic Materials ,law.invention ,Condensed Matter::Materials Science ,Optics ,law ,Condensed Matter::Superconductivity ,Picosecond ,Optoelectronics ,Interfacial thermal resistance ,Thin film ,business - Abstract
Picosecond nonequilibrium and slow bolometric responses to infrared radiation from a patterned high-T c superconducting (HTS) film in resistive and normal states deposited onto LaAlO3, NdGaO3, and MgO substrates were investigated using both pulse and modulation techniques. The response time of 35 ps to a laser pulse of 17 ps FWHM has been observed. The intrinsic response time of the fast process is expected to be about a few picoseconds. The modulation technique, being free from the disadvantages of pulse methods (poor sensitivity, limited dynamic range), makes the detailed study of a number of relaxation processes possible. Besides the nonequilibrium response, two kinds of bolometric processes, namely phonon transport through the film-substrate interface and phonon thermal diffusion in a substrate, manifest themselves in certain frequency dependences.
- Published
- 1995
40. Energy-resolved detection of single infrared photons with {\lambda} = 8 {\mu}m using a superconducting microbolometer
- Author
-
Alexander Soibel, Daniel F. Santavicca, Boris S. Karasik, Daniel E. Prober, David Olaya, Sergey V. Pereverzev, and Michael Gershenson
- Subjects
Photon ,Materials science ,Physics - Instrumentation and Detectors ,Physics and Astronomy (miscellaneous) ,business.industry ,Infrared ,Bolometer ,Photodetector ,Physics::Optics ,Microbolometer ,Photon energy ,Photon counting ,law.invention ,law ,Optoelectronics ,business ,Spectroscopy ,Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
We report on the detection of single photons with {\lambda} = 8 {\mu}m using a superconducting hot-electron microbolometer. The sensing element is a titanium transition-edge sensor with a volume ~ 0.1 {\mu}m^3 fabricated on a silicon substrate. Poisson photon counting statistics including simultaneous detection of 3 photons was observed. The width of the photon-number peaks was 0.11 eV, 70% of the photon energy, at 50-100 mK. This achieved energy resolution is one of the best figures reported so far for superconducting devices. Such devices can be suitable for single photon calorimetric spectroscopy throughout the mid-infrared and even the far-infrared., Comment: 17 pages, 5 figures. Accepted to Applied Physics Letters
- Published
- 2012
41. Nanobolometers for THz Photon Detection
- Author
-
Andrei Sergeev, Boris S. Karasik, and Daniel E. Prober
- Subjects
Physics ,Radiation ,Photon ,Physics - Instrumentation and Detectors ,business.industry ,Electromagnetic spectrum ,Terahertz radiation ,Detector ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,Wavelength ,Optics ,Electrical and Electronic Engineering ,business ,Astrophysics - Instrumentation and Methods for Astrophysics ,Noise-equivalent power ,Quantum ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
This article reviews the state of rapidly emerging terahertz hot-electron nanobolometers (nano-HEB), which are currently among of the most sensitive radiation power detectors at submillimeter wavelengths. With the achieved noise equivalent power close to 10^{-19} W/Hz^{1/2} and potentially capable of approaching NEP ~ 10^{-20} W/Hz^{1/2}, nano-HEBs are very important for future space astrophysics platforms with ultralow submillimeter radiation background. The ability of these sensors to detect single low-energy photons opens interesting possibilities for quantum calorimetry in the mid-infrared and even in the farinfrared parts of the electromagnetic spectrum. We discuss the competition in the field of ultrasensitive detectors, the physics and technology of nano-HEBs, recent experimental results, and perspectives for future development., Comment: 16 pages, 12 figures, 128 references
- Published
- 2012
- Full Text
- View/download PDF
42. Nonequilibrium and bolometric photoresponse in patterned YBa2Cu3O7−δthin films
- Author
-
V. Trifonov, M. Danerud, E. M. Gershenzon, Mikael Lindgren, Boris S. Karasik, M. A. Zorin, Dag Winkler, and G.N. Gol'tsman
- Subjects
Materials science ,Phonon ,business.industry ,Bolometer ,General Physics and Astronomy ,Substrate (electronics) ,Laser ,Epitaxy ,Molecular physics ,law.invention ,Full width at half maximum ,Wavelength ,law ,Optoelectronics ,Thin film ,business - Abstract
Epitaxial laser deposited YBa2Cu3O7−δ films of ∼50 nm thickness were patterned into detectors consisting of ten parallel 1 μm wide strips in order to study nonequilibrium and bolometric effects. Typically, the patterned samples had critical temperatures around 86 K, transition widths around 2 K and critical current densities above 1×106A/cm2 at 77 K. Pulsed laser measurements at 0.8 μm wavelength (17 ps full width at half maximum) showed a ∼30 ps response, attributed to electron heating, followed by a slower bolometric decay. Amplitude modulation in the band fmod=100 kHz–10 GHz of a laser with wavelength λ=0.8 μm showed two different thermal relaxations in the photoresponse. Phonon escape from the film (∼3 ns) is the limiting process, followed by heat diffusion in the substrate. Similar relaxations were also seen for λ=10.6 μm. The photoresponse measurements were made with the film in the resistive state and extended into the normal state. These states were created by supercritical bias currents. Measurem...
- Published
- 1994
43. Dynamics of the response to microwave radiation in YBa2Cu3O7−x hot-electron bolometer mixers
- Author
-
William R. McGrath, Boris S. Karasik, Konstantin Ilin, Gert de Lange, Oliver Harnack, and Michael Siegel
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Phonon ,Local oscillator ,Bolometer ,Electron ,Radiation ,law.invention ,Thermal conductivity ,Intermediate frequency ,law ,Optoelectronics ,business ,Microwave - Abstract
We present a systematic study of the intermediate frequency (IF) bandwidth of hot-electron bolometer mixers made from YBa2Cu3O7−x high-temperature superconductive thin films fabricated on substrates with high thermal conductivity (MgO and sapphire). At a local oscillator frequency of 100 GHz, a strong dependence of the IF bandwidth on the bias point and temperature has been experimentally found. Moreover, an unexpected IF bandwidth variation has been detected in a broad range of operating frequencies (1–480 GHz). Besides conventional bolometric mixing mechanisms associated with thermalization of electrons and phonons, the contribution of direct interaction between radiation and magnetic vortices in the YBa2Cu3O7−x film may be responsible for the observed effects.
- Published
- 2001
44. Development of the nano-HEB array for low-background far-IR applications
- Author
-
Daniel F. Santavicca, Faustin Carter, David Olaya, Michael Gershenson, Dennis G. Harding, Daniel E. Prober, Boris S. Karasik, Sergey V. Pereverzev, J. Kawamura, Bruce Bumble, Henry G. LeDuc, Peter K. Day, Robin Cantor, Steve P. Monacos, Holland, Wayne S., and Zmuidzinas, Jonas
- Subjects
Physics ,Photon ,Optics ,Infrared ,business.industry ,Detector ,business ,Phonon noise ,Noise (electronics) ,Microwave ,Photon counting ,Particle detector - Abstract
We present an overview of the recent progress made in the development of a far-IR array of ultrasensitive hot-electron nanobolometers (nano-HEB) made from thin titanium (Ti) films. We studied electrical noise, signal and noise bandwidth, single-photon detection, optical noise equivalent power (NEP), and a microwave SQUID (MSQUID) based frequency domain multiplexing (FDM) scheme. The obtained results demonstrate the very low electrical NEP down to 1.5 × 10^(-20) W/Hz^(1/2) at 50 mK determined by the dominating phonon noise. The NEP increases with temperature as ~ T^3 reaching ~10^(-17) W/Hz^(1/2) at the device critical temperature T_C = 330-360 mK. Optical NEP = 8.6 × 10^(-18) W/Hz^(1/2) at 357 mK and 1.4 × 10^(-18) W/Hz^(1/2) at 100 mK respectively, agree with thermal and electrical data. The optical coupling efficiency provided by a planar antenna was greater than 50%. Single 8-μm photons have been detected for the first time using a nano-HEB operating at 50-200 mK thus demonstrating a potential of these detectors for future photon-counting applications in mid-IR and far-IR. In order to accommodate the relatively high detector speed (~μs at 300 mK, ~100 μs at 100 mK), an MSQUID based FDM multiplexed readout with GHz carrier frequencies has been built. Both the readout noise ~2 pA/Hz^(1/2) and the bandwidth > 150 kHz are suitable for nano-HEB detectors.
- Published
- 2010
45. Picosecond YBa2Cu3O7−δdetector for far‐infrared radiation
- Author
-
R. Steinke, Boris S. Karasik, M. A. Heusinger, Karl Friedrich Renk, A. D. Semenov, E. M. Gershenzon, G.N. Gol'tsman, Peter Lang, W. Schatz, and R. S. Nebosis
- Subjects
Range (particle radiation) ,Materials science ,business.industry ,Detector ,Analytical chemistry ,General Physics and Astronomy ,Radiation ,Laser ,Particle detector ,law.invention ,Optics ,Far infrared ,law ,Picosecond ,business ,Noise-equivalent power - Abstract
We report on a picosecond YBa2Cu3O7−δ detector for far‐infrared radiation. The detector, consisting of a current carrying structure cooled to liquid‐nitrogen temperature, was studied by use of ultrashort laser pulses from an optically pumped far‐infrared laser in the frequency range from 25 to 215 cm−1. We found that the sensitivity (1 mV/W) was almost constant in this frequency range. We estimated a noise equivalent power of less than 5×10−7 W Hz−1/2. Taking into account the results of a mixing experiment (in the frequency range from 4 to 30 cm−1) we suggest that the response time of the detector was few picoseconds.
- Published
- 1992
46. Multiplexing of Hot-Electron Nanobolometers Using Microwave SQUIDs
- Author
-
Boris S. Karasik, Peter K. Day, Jonathan H. Kawamura, Bruce Bumble, Henry G. LeDuc, Betty Young, Blas Cabrera, and Aaron Miller
- Subjects
Materials science ,business.industry ,Amplifier ,Bolometer ,Noise (electronics) ,Signal ,law.invention ,law ,Baseband ,Electronic engineering ,Optoelectronics ,Time domain ,business ,Phonon noise ,Microwave - Abstract
We have obtained the first data on the multiplexed operation of titanium hot-electron bolometers (HEB). Because of their low thermal conductance and small electron heat capacity nanobolometers are particularly interesting as sensors for far-infrared spectroscopy and mid- and near-IR calorimetry. However, the short time constant of these devices (approximately microseconds at 300-400 mK) makes time domain or audio-frequency domain multiplexing impractical. The Microwave SQUID (MSQUID) approach pursued in this work uses dc SQUIDs coupled to X-band microresonators which are, in turn, coupled to a transmission line. We used a 4-element array of Ti HEBs operated at 415 mK in a He3 dewar with an optical fiber access. The microwave signal exhibited 10-MHz wide resonances at individual MSQUD frequencies between 9 GHz and 10 GHz. The resonance depth is modulated by the current through the bolometer via a change of the SQUID flux state. The transmitted signal was amplified by a cryogenic amplifier and downconverted to baseband using an IQ mixer. A 1-dB per ??/2 responsivity was sufficient for keeping the system noise at the level of ~ 2 pA/Hz1/2. This is more than an order of magnitude smaller than phonon noise in the HEB. The devices were able to detect single near- IR photons (1550 nm) with a time constant of 3.5 ?s. Follow-on work will scale the array to larger size and will address the microwave frequency signal generation and processing using a digital transceiver.
- Published
- 2009
47. Submicron-long HTS hot-electron mixers
- Author
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Boris S. Karasik, Oliver Harnack, A. W. Kleinsasser, William R. McGrath, and Jeff B. Barner
- Subjects
Superconductivity ,Materials science ,business.industry ,Local oscillator ,Bandwidth (signal processing) ,Bolometer ,Mixer noise ,Metals and Alloys ,Condensed Matter Physics ,law.invention ,Intermediate frequency ,law ,Materials Chemistry ,Ceramics and Composites ,Sapphire ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Hot electron - Abstract
We have measured the device length and temperature dependence of the intermediate frequency (IF) bandwidth and noise of hot-electron bolometer (HEB) mixers made from a high-T c superconductor. Mixer devices with lengths (L) between 50 nm and 1 μm were fabricated from 25-35 nm thick YBCO films on MgO and sapphire substrates. Bandwidth measurements were made using signal and local oscillator (LO) frequencies in the range 1-20 GHz. At low operation temperatures the IF bandwidths were about 100 MHz and several hundred MHz for devices on MgO and sapphire, respectively. At higher operation temperatures, where self-heating disappeared and flux-flow effects define the shape of the I-V characteristic, the measured IF bandwidth increased significantly. The temperature and IF dependence of absolute conversion efficiencies determined from noise measurements are in good agreement with the bandwidth data. At 2.7 GHz LO frequency the single-side-band mixer noise temperature of a 50 nm long HEB on MgO was about 8000 K.
- Published
- 1999
48. Ultra-sensitive hot-electron nanobolometers for THz astrophysics
- Author
-
Sergey V. Pereverzev, R. Cantor, Michael Gershenson, Jian Wei, David Olaya, Andrei Sergeev, and Boris S. Karasik
- Subjects
Physics ,Photon ,business.industry ,Orders of magnitude (temperature) ,Phonon ,Terahertz radiation ,Bolometer ,Photon counting ,law.invention ,Thermal conductivity ,law ,Optoelectronics ,Photonics ,business - Abstract
The background-limited spectral imaging of the early Universe requires terahertz (THz) detectors with the sensitivity 2-3 orders of magnitude better than that of the state-of-the-art bolometers. To realize this sensitivity without sacrificing the operating speed, the sensing element of a bolometric detector should have an exceptionally high thermal isolation from the environment combined with an ultrasmall heat capacity. We have demonstrated that this goal can be achieved by realizing a superconducting hot-electron nanobolometer whose design blocks photon and phonon energy exchange through its contact leads. The remaining coupling due to electron-phonon interaction provides thermal control at a level of one thousandth of the quantum of thermal conductance GQ ap 1 [pW/K] times T. These hot-electron nanobolometers with a heat capacity of ~ 0.1 aJ/K will be sufficiently sensitive for registration of single THz photons. These devices are very promising for submillimeter astronomy and other applications based on quantum calorimetry and photon counting.
- Published
- 2008
49. Electrical NEP in hot-electron titanium superconducting bolometers
- Author
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Andrei Sergeev, Boris S. Karasik, David Olaya, Sergey V. Pereverzev, Michael Gershenson, and Jian Wei
- Subjects
Physics ,business.industry ,Bolometer ,Johnson–Nyquist noise ,Noise (electronics) ,Particle detector ,law.invention ,SQUID ,Optics ,law ,Optoelectronics ,Transition edge sensor ,business ,Phonon noise ,Noise-equivalent power - Abstract
We are presenting the current progress on the titanium (Ti) hot-electron transition-edge devices. The ultimate goal of this work is to develop a submillimeter Hot-Electron Direct Detector (HEDD) with the noise equivalent power NEP = 10-18-10-20 W/Hz1/2 for the moderate resolution spectroscopy and Cosmic Microwave Background (CMB) studies on future space telescope (e.g., SPICA, SAFIR, SPECS, CMBPol) with cryogenically cooled (~ 4-5 K) mirrors. Recentlyi, we have achieved the extremely low thermal conductance (~ 20 fW/K at 300 mK and ~ 0.1 fW/K at 40 mK) due to the electron-phonon decoupling in Ti nanodevices with niobium (Nb) Andreev contacts. This thermal conductance translates into the "phonon-noise" NEP ≈ 3×10-21 W/Hz1/2 at 40 mK and NEP ≈ 3×10-19 W/Hz1/2 at 300 mK. These record data indicate the great potential of the hot-electron detector for meeting many application needs. Beside the extremely low phonon-noise NEP, the nanobolometers have a very low electron heat capacitance that makes them promising as detectors of single THz photonsii. As the next step towards the practical demonstration of the HEDD, we fabricated and tested somewhat larger than in Ref.1 devices (~ 6 μm × 0.35 μm × 40 nm) whose critical temperature is well reproduced in the range 300-350 mK. The output electrical noise measured in these devices with a low-noise dc SQUID is dominated by the thermal energy fluctuations (ETF) aka "phonon noise". This indicates the high electrothermal loop gain that effectively suppresses the contributions of the Johnson noise and the amplifier (SQUID) noise. The electrical NEP = 6.7×10-18 W/Hz1/2 derived from these measurements is in good agreement with the predictions based on the thermal conductance data. The very low NEP and the high speed (~ μs) are a unique combination not found in other detectors.
- Published
- 2008
50. Ultrasensitive hot-electron nanobolometers for terahertz astrophysics
- Author
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Michael Gershenson, Jian Wei, Andrei Sergeev, Boris S. Karasik, David Olaya, and Sergey V. Pereverzev
- Subjects
Silicon ,Photon ,Terahertz gap ,Hot Temperature ,Electromagnetic spectrum ,Terahertz radiation ,Surface Properties ,Astronomy ,Niobium ,Biomedical Engineering ,FOS: Physical sciences ,Bioengineering ,Electrons ,Astrophysics ,Electron ,Sensitivity and Specificity ,Submillimetre astronomy ,law.invention ,Optics ,Electromagnetic Fields ,law ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Nanotechnology ,Polymethyl Methacrylate ,General Materials Science ,Electrical and Electronic Engineering ,Piperidones ,Physics ,Titanium ,Photons ,Condensed Matter - Mesoscale and Nanoscale Physics ,business.industry ,Bolometer ,Astrophysics (astro-ph) ,Silicon Compounds ,Thermal Conductivity ,Equipment Design ,Condensed Matter Physics ,Silicon Dioxide ,Atomic and Molecular Physics, and Optics ,Photon counting ,Condensed Matter - Other Condensed Matter ,Energy Transfer ,business ,Other Condensed Matter (cond-mat.other) - Abstract
The background-limited spectral imaging of the early Universe requires spaceborne terahertz (THz) detectors with the sensitivity 2-3 orders of magnitude better than that of the state-of-the-art bolometers. To realize this sensitivity without sacrificing operating speed, novel detector designs should combine an ultrasmall heat capacity of a sensor with its unique thermal isolation. Quantum effects in thermal transport at nanoscale put strong limitations on the further improvement of traditional membrane-supported bolometers. Here we demonstrate an innovative approach by developing superconducting hot-electron nanobolometers in which the electrons are cooled only due to a weak electron-phonon interaction. At T, 19 pages, 3 color figures
- Published
- 2008
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