The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
M S Shur - One of the best experts on this subject based on the ideXlab platform.
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ultrashort pulse detection and response time analysis using Plasma Wave terahertz field effect transistors
IEEE Transactions on Electron Devices, 2021Co-Authors: Yuhui Zhang, M S ShurAbstract:We report on the response characteristics of plasmonic terahertz field-effect transistors (TeraFETs) fed with femtosecond and picosecond pulses. Varying the pulsewidth ( ${t}_{\textit {pw}}$ ) from 10−15 s to 10−10 s under a constant input power condition revealed two distinctive pulse detection modes. In the short pulse mode ( ${t}_{\textit {pw}} \ll {L}/{s}$ , where ${L}$ is the gated channel length and ${s}$ is the Plasma velocity), the source-to-drain voltage response is a sharp pulse oscillatory decay preceded by a delay time on the order of ${L}/{s}$ . The Plasma Wave travels along the channel like the shallow water Wave with a relatively narrow Wave package. In the long pulse mode ( ${t}_{\textit {pw}} > {L}/{s}$ ), the response profile has two oscillatory decay processes and the propagation of Plasma Wave is analogous to an oscillating rod with one side fixed. The ultimate response time at the long pulse mode is significantly higher than that under the short pulse conditions. The detection conditions under the long pulse mode are close to the step response condition, and the response time conforms well to the analytical theory for the step function response. The simulated Waveform agrees well with the measured pulse response. Our results show that the measurements of the pulse response enable the material parameter extraction from the pulse response data (including the effective mass, kinematic viscosity, and momentum relaxation time).
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ultrashort pulse detection and response time analysis using Plasma Wave terahertz field effect transistors
arXiv: Applied Physics, 2020Co-Authors: Yuhui Zhang, M S ShurAbstract:We report on the response characteristics of plasmonic terahertz field-effect transistors (TeraFETs) fed with femtosecond and picosecond pulses. Varying the pulse width (tpw) from 10-15 s to 10-10 s under a constant input power condition revealed two distinctive pulse detection modes. In the short pulse mode (tpw L/s), the response profile has two oscillatory decay processes and the propagation of Plasma Wave is analogues to oscillating rod with one side fixed. The ultimate response time at the long pulse mode is significantly higher than that under the short pulse conditions. The detection conditions under the long pulse mode are close to the step response condition, and the response time conforms well to the analytical theory for the step function response. The simulated Waveform agrees well with the measured pulse response. Our results show that the measurements of the pulse response enable the material parameter extraction from the pulse response data (including the effective mass, kinematic viscosity and momentum relaxation time).
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graphene based Plasma Wave devices for terahertz applications
Applied Physics Letters, 2020Co-Authors: Victor Ryzhii, Taiichi Otsuji, M S ShurAbstract:Unique properties of graphene are combined to enable graphene plasmonic devices that could revolutionize the terahertz (THz) electronic technology. A high value of the carrier mobility allows us to excite resonant Plasma Waves. The graphene bipolar nature allows for different mechanisms of Plasma Wave excitation. Graphene bilayer and multilayer structures make possible improved THz device configurations. The ability of graphene to form a high quality heterostructure with h-BN, black phosphorus, and other materials systems supports advanced heterostructure devices comprised of the best properties of graphene and other emerging materials. In particular, using black phosphorus compounds for cooling electron–hole Plasma in graphene could dramatically improve the conditions for THz lasing. High optical phonon energy allows for reaching higher Plasma frequencies that are supported by high sheet carrier densities in graphene. Recent improvements in graphene technology combined with a better understanding of the device physics of graphene THz plasmonics and graphene plasmonic device designs hold promise to make graphene THz plasmonic technology one of the key graphene applications. Commercialization of plasmonic graphene technology is facing the same challenges as other graphene applications, which have difficulties in producing uniform large graphene layers, bilayers, and heterostructures of high quality and making good low resistance stable Ohmic contacts. The time projection for large scale graphene electronic device applications now extends into the 2030s. However, emerging graphene mass production technologies might bring commercial applications of the graphene plasmonic terahertz technology closer.
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Plasma Wave resonant detection of femtosecond pulsed terahertz radiation by a nanometer field effect transistor
Applied Physics Letters, 2005Co-Authors: F Teppe, W Knap, S L Rumyantsev, D Veksler, Yu V Kachorovski, A P Dmitriev, Xu Xie, X C Zhang, M S ShurAbstract:We report on the room-temperature, resonant detection of femtosecond pulsed terahertz radiation obtained by optical rectification in a ZnTe crystal. The detection was realized using a 250nm gate length GaAs∕AlGaAs heterostructure field-effect transistor. We show that physical mechanism of the detection is related to the Plasma Waves excited in the transistor channel. The detection is strongly enhanced by increasing the drain current and driving the transistor into the Plasma Wave instability region. Our results clearly show that Plasma Wave nanometer transistors can be efficient and fast detectors for terahertz spectroscopic imaging based on the femtosecond pulsed THz sources.
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Plasma Wave detection of sub terahertz and terahertz radiation by silicon field effect transistors
Applied Physics Letters, 2004Co-Authors: W Knap, F Teppe, N Dyakonova, Y M Meziani, J Lusakowski, F Boeuf, T Skotnicki, D K Maude, S L Rumyantsev, M S ShurAbstract:We report on experiments on photoresponse to sub-THz (120GHz) radiation of Si field-effect transistors (FETs) with nanometer and submicron gate lengths at 300K. The observed photoresponse is in agreement with predictions of the Dyakonov–Shur Plasma Wave detection theory. This is experimental evidence of the Plasma Wave detection by silicon FETs. The Plasma Wave parameters deduced from the experiments allow us to predict the nonresonant and resonant detection in THz range by nanometer size silicon devices—operating at room temperature.
F Teppe - One of the best experts on this subject based on the ideXlab platform.
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Plasma Wave detectors for terahertz wireless communication
IEEE Electron Device Letters, 2012Co-Authors: S Blin, F Teppe, Dominique Coquillat, L Tohme, Shintaro Hisatake, K Arakawa, P Nouvel, A Penarier, J Torres, L VaraniAbstract:We report on terahertz wireless communication experiments at 0.3 THz using 250-nm gate-length GaAs/AlGaAs field-effect transistor (FET) as a detector and unitraveling-carrier photodiode as a source. The physical mechanism of the detection process is terahertz Wave rectification on nonlinearities related to overdamped Plasma oscillations in the transistor channel. We present an experimental study of rectification bandwidth and show for the first time that room-temperature direct detection with modulation bandwidth of up to 8 GHz can be achieved, thus showing that nanometer-sized FETs can be used as valuable detectors in all-solid-state terahertz wireless communication systems.
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oblique modes effect on terahertz Plasma Wave resonant detection in ingaas inalas multichannel transistors
Applied Physics Letters, 2008Co-Authors: A Shchepetov, Stephane Boubangatombet, F Teppe, D Coquillat, S Nadar, C Gardes, Y Roelens, A Cappy, S Bollaert, N DyakonovaAbstract:We report on the demonstration of narrow terahertz Plasma Wave resonant detection at low temperature in 200nm gate length InGaAs∕InAlAs multichannel high electron mobility transistors. We observe that the resonant detection linewidth is smaller than in full channel high electron mobility transistors. We interpret this shrinking by the effect of multichannel geometry that does not allow oblique Plasma mode propagation along the channel.
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current driven resonant Plasma Wave detection of terahertz radiation toward the dyakonov shur instability
Applied Physics Letters, 2008Co-Authors: Stephane Boubangatombet, F Teppe, D Coquillat, S Nadar, N Dyakonova, H Videlier, W Knap, A Shchepetov, C Gardes, Y RoelensAbstract:The experiments on the dc current influence on resonant terahertz Plasma Wave detection in InGaAs∕InAlAs multichannel high electron mobility transistors are reported. We observed the line width shrinking when a dc current is applied. We show that this line width decrease is due to the current induced reduction of Plasma Wave damping and takes place because the current drives the system toward the Dyakonov-Shur Plasma Wave instability.
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room temperature detection and emission of terahertz radiation by Plasma oscillations in nanometer size transistors
International Conference on Infrared Millimeter and Terahertz Waves, 2007Co-Authors: W Knap, F Teppe, D Coquillat, N Dyakonova, A Shchepetov, S Boubanga, El A Fatimy, C Gaquiere, S BollaertAbstract:The channel of nanometre field effect transistor can act as a resonant cavity for Plasma Waves. The frequency of these Plasma Waves is in the Terahertz range and can be tuned by the gate bias. During the last few years Terahertz detection and emission related to Plasma Wave instabilities in nanometre size field effect transistors was demonstrated experimentally. In this work we review the recent experimental results on the resonant Plasma Wave detection and emission at room temperature.
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Plasma Wave detection of terahertz radiation by silicon field effects transistors responsivity and noise equivalent power
Applied Physics Letters, 2006Co-Authors: R Tauk, F Teppe, D Coquillat, W Knap, Y M Meziani, F Boeuf, T Skotnicki, S Boubanga, C Gallon, C FenouilletberangerAbstract:Si metal oxide semiconductor field effect transistors (MOSFETs) with the gate lengths of 120–300nm have been studied as room temperature Plasma Wave detectors of 0.7THz electromagnetic radiation. In agreement with the Plasma Wave detection theory, the response was found to depend on the gate length and the gate bias. The obtained values of responsivity (⩽200V∕W) and noise equivalent power (⩾10−10W∕Hz0.5) demonstrate the potential of Si MOSFETs as sensitive detectors of terahertz radiation.
W Knap - One of the best experts on this subject based on the ideXlab platform.
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Plasma Wave terahertz detection mediated by topological insulators surface states
Nano Letters, 2016Co-Authors: Leonardo Viti, D Coquillat, W Knap, Antonio Politano, K A Kokh, Ziya S Aliev, M B Babanly, O E Tereshchenko, Evgueni V ChulkovAbstract:Topological insulators (TIs) represent a novel quantum state of matter, characterized by edge or surface-states, showing up on the topological character of the bulk Wave functions. Allowing electrons to move along their surface, but not through their inside, they emerged as an intriguing material platform for the exploration of exotic physical phenomena, somehow resembling the graphene Dirac-cone physics, as well as for exciting applications in optoelectronics, spintronics, nanoscience, low-power electronics, and quantum computing. Investigation of topological surface states (TSS) is conventionally hindered by the fact that in most of experimental conditions the TSS properties are mixed up with those of bulk-states. Here, we activate, probe, and exploit the collective electronic excitation of TSS in the Dirac cone. By engineering Bi2Te(3–x)Sex stoichiometry, and by gating the surface of nanoscale field-effect-transistors, exploiting thin flakes of Bi2Te2.2Se0.8 or Bi2Se3, we provide the first demonstratio...
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current driven resonant Plasma Wave detection of terahertz radiation toward the dyakonov shur instability
Applied Physics Letters, 2008Co-Authors: Stephane Boubangatombet, F Teppe, D Coquillat, S Nadar, N Dyakonova, H Videlier, W Knap, A Shchepetov, C Gardes, Y RoelensAbstract:The experiments on the dc current influence on resonant terahertz Plasma Wave detection in InGaAs∕InAlAs multichannel high electron mobility transistors are reported. We observed the line width shrinking when a dc current is applied. We show that this line width decrease is due to the current induced reduction of Plasma Wave damping and takes place because the current drives the system toward the Dyakonov-Shur Plasma Wave instability.
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room temperature detection and emission of terahertz radiation by Plasma oscillations in nanometer size transistors
International Conference on Infrared Millimeter and Terahertz Waves, 2007Co-Authors: W Knap, F Teppe, D Coquillat, N Dyakonova, A Shchepetov, S Boubanga, El A Fatimy, C Gaquiere, S BollaertAbstract:The channel of nanometre field effect transistor can act as a resonant cavity for Plasma Waves. The frequency of these Plasma Waves is in the Terahertz range and can be tuned by the gate bias. During the last few years Terahertz detection and emission related to Plasma Wave instabilities in nanometre size field effect transistors was demonstrated experimentally. In this work we review the recent experimental results on the resonant Plasma Wave detection and emission at room temperature.
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Plasma Wave detection of terahertz radiation by silicon field effects transistors responsivity and noise equivalent power
Applied Physics Letters, 2006Co-Authors: R Tauk, F Teppe, D Coquillat, W Knap, Y M Meziani, F Boeuf, T Skotnicki, S Boubanga, C Gallon, C FenouilletberangerAbstract:Si metal oxide semiconductor field effect transistors (MOSFETs) with the gate lengths of 120–300nm have been studied as room temperature Plasma Wave detectors of 0.7THz electromagnetic radiation. In agreement with the Plasma Wave detection theory, the response was found to depend on the gate length and the gate bias. The obtained values of responsivity (⩽200V∕W) and noise equivalent power (⩾10−10W∕Hz0.5) demonstrate the potential of Si MOSFETs as sensitive detectors of terahertz radiation.
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Plasma Wave resonant detection of femtosecond pulsed terahertz radiation by a nanometer field effect transistor
Applied Physics Letters, 2005Co-Authors: F Teppe, W Knap, S L Rumyantsev, D Veksler, Yu V Kachorovski, A P Dmitriev, Xu Xie, X C Zhang, M S ShurAbstract:We report on the room-temperature, resonant detection of femtosecond pulsed terahertz radiation obtained by optical rectification in a ZnTe crystal. The detection was realized using a 250nm gate length GaAs∕AlGaAs heterostructure field-effect transistor. We show that physical mechanism of the detection is related to the Plasma Waves excited in the transistor channel. The detection is strongly enhanced by increasing the drain current and driving the transistor into the Plasma Wave instability region. Our results clearly show that Plasma Wave nanometer transistors can be efficient and fast detectors for terahertz spectroscopic imaging based on the femtosecond pulsed THz sources.
W P Leemans - One of the best experts on this subject based on the ideXlab platform.
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nonlinear pulse propagation and phase velocity of laser driven Plasma Waves
Physical Review Letters, 2011Co-Authors: C.b. Schroeder, E Esarey, C Benedetti, W P LeemansAbstract:Laser evolution and Plasma Wave excitation by a relativistically intense short-pulse laser in underdense Plasma are investigated in the broad pulse limit, including the effects of pulse steepening, frequency redshifting, and energy depletion. The nonlinear Plasma Wave phase velocity is shown to be significantly lower than the laser group velocity and further decreases as the pulse propagates owing to laser evolution. This lowers the thresholds for trapping and Wave breaking and reduces the energy gain and efficiency of laser-Plasma accelerators that use a uniform Plasma profile.
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laser driven Plasma Wave electron accelerators
Physics Today, 2009Co-Authors: W P Leemans, E EsareyAbstract:Surfing a Plasma Wave, a bunch of electrons or positrons can experience much higher accelerating gradients than a conventional RF linac could provide.
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frequency chirp and pulse shape effects in self modulated laser wakefield accelerators
Physics of Plasmas, 2003Co-Authors: C.b. Schroeder, J Van Tilborg, C G R Geddes, J L Faure, Cs. Toth, B A Shadwick, E Esarey, W P LeemansAbstract:The effect of asymmetric laser pulses on Plasma Wave excitation in a self-modulated laser wakefield accelerator is examined. Laser pulse shape and frequency chirp asymmetries, controlled experimentally in the laser system through a grating pair compressor, are shown to strongly enhance measured electron yields for certain asymmetries. It is shown analytically that a positive (negative) frequency chirp enhances (suppresses) the growth rate of the Raman forward scattering and near-forward Raman sidescatter instabilities, but is of minimal importance for the experimental parameters. Temporal laser pulse shapes with fast rise times (≲ Plasma period) are shown to generate larger wakes (compared to slow rise time pulses) which seed the growth of the Plasma Wave, resulting in enhanced electron yield.
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ultrahigh gradient acceleration of injected eletrons by laser excited relativistic electron Plasma Waves
Physical Review Letters, 1993Co-Authors: C E Clayton, W P Leemans, M J Everett, K A Marsh, A Dyson, Amit K Lal, R Williams, C JoshiAbstract:High-gradient acceleration of externally injected 2.1-MeV electrons by a laser beat Wave driven relativistic Plasma Wave has been demonstrated for the first time. Electrons with energies up to the detection limit of 9.1 MeV were detected when such a Plasma Wave was resonantly excited using a two-frequency laser. This implies a gradient of 0.7 GeV/m, corresponding to a Plasma-Wave amplitude of more than 8%. The electron signal was below detection threshold without injection or when the laser was operated on a single frequency.
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ultrahigh gradient acceleration of injected electrons by laser excited relativistic electron Plasma Waves
Physical Review Letters, 1993Co-Authors: C E Clayton, W P Leemans, M J Everett, K A Marsh, A Dyson, Amit K Lal, R Williams, C JoshiAbstract:High-gradient acceleration of externally injected 2.1-MeV electrons by a laser beat Wave driven relativistic Plasma Wave has been demonstrated for the first time. Electrons with energies up to the detection limit of 9.1 MeV were detected when such a Plasma Wave was resonantly excited using a two-frequency laser. This implies a gradient of 0.7 GeV/m, corresponding to a Plasma-Wave amplitude of more than 8%. The electron signal was below detection threshold without injection or when the laser was operated on a single frequency.
W S Kurth - One of the best experts on this subject based on the ideXlab platform.
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Plasma densities near and beyond the heliopause from the Voyager 1 and 2 Plasma Wave instruments
Nature Astronomy, 2019Co-Authors: D. A. Gurnett, W S KurthAbstract:The heliopause is the boundary between the hot heliospheric (solar wind) Plasma and the relatively cold interstellar Plasma. Pressure balance considerations show that there should be a large (factor of 20 to 50) density increase across the heliopause. Here we report electron density measurements from the Voyager 1 and 2 Plasma Wave instruments near and beyond the heliopause. The Plasma density in the outer heliosphere is typically about 0.002 cm^−3. The first electron density measured by the Voyager 2 Plasma Wave instrument in the interstellar medium, 0.039 cm^−3 ± 15%, was on 30 January 2019 at a heliocentric radial distance of 119.7 au. The density jump, about a factor of 20, confirms that Voyager 2 crossed the heliopause. The new density is very similar to the first density measured in the interstellar medium by the Voyager 1 Plasma Wave instrument, 0.055 cm^−3, on 23 October 2013 at a radial distance of 122.6 au. These small differences in the densities and radial distances are probably due to the relative locations of the spacecraft in the boundary layer that forms in the interstellar Plasma just beyond the heliopause. This Article reports measurements from the Plasma Wave instruments of the Voyager spacecraft as they passed from the heliosphere into interstellar space. The Voyager 2 instrument recorded an electron density jump of a factor of 20, similar to that from Voyager 1 several years previously.
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evidence of a plume on europa from galileo magnetic and Plasma Wave signatures
Nature Astronomy, 2018Co-Authors: Xianzhe Jia, M G Kivelson, K K Khurana, W S KurthAbstract:The icy surface of Jupiter’s moon, Europa, is thought to lie on top of a global ocean1–4. Signatures in some Hubble Space Telescope images have been associated with putative water plumes rising above Europa’s surface5,6, providing support for the ocean theory. However, all telescopic detections reported were made at the limit of sensitivity of the data5–7, thereby calling for a search for plume signatures in in-situ measurements. Here, we report in-situ evidence of a plume on Europa from the magnetic field and Plasma Wave observations acquired on Galileo’s closest encounter with the moon. During this flyby, which dropped below 400 km altitude, the magnetometer 8 recorded an approximately 1,000-kilometre-scale field rotation and a decrease of over 200 nT in field magnitude, and the Plasma Wave Spectrometer 9 registered intense localized Wave emissions indicative of a brief but substantial increase in Plasma density. We show that the location, duration and variations of the magnetic field and Plasma Wave measurements are consistent with the interaction of Jupiter’s corotating Plasma with Europa if a plume with characteristics inferred from Hubble images were erupting from the region of Europa’s thermal anomalies. These results provide strong independent evidence of the presence of plumes at Europa.
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electron densities inferred from Plasma Wave spectra obtained by the Waves instrument on van allen probes
Journal of Geophysical Research, 2015Co-Authors: W S Kurth, G B Hospodarsky, S De Pascuale, J B Faden, C A Kletzing, S A Thaller, J R WygantAbstract:The twin Van Allen Probe spacecraft, launched in August 2012, carry identical scientific payloads. The Electric and Magnetic Field Instrument Suite and Integrated Science suite includes a Plasma Wave instrument (Waves) that measures three magnetic and three electric components of Plasma Waves in the frequency range of 10 Hz to 12 kHz using triaxial search coils and the Electric Fields and Waves triaxial electric field sensors. The Waves instrument also measures a single electric field component of Waves in the frequency range of 10 to 500 kHz. A primary objective of the higher-frequency measurements is the determination of the electron density ne at the spacecraft, primarily inferred from the upper hybrid resonance frequency fuh. Considerable work has gone into developing a process and tools for identifying and digitizing the upper hybrid resonance frequency in order to infer the electron density as an essential parameter for interpreting not only the Plasma Wave data from the mission but also as input to various magnetospheric models. Good progress has been made in developing algorithms to identify fuh and create a data set of electron densities. However, it is often difficult to interpret the Plasma Wave spectra during active times to identify fuh and accurately determine ne. In some cases, there is no clear signature of the upper hybrid band, and the low-frequency cutoff of the continuum radiation is used. We describe the expected accuracy of ne and issues in the interpretation of the electrostatic Wave spectrum.
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detection of a strongly negative surface potential at saturn s moon hyperion
Geophysical Research Letters, 2014Co-Authors: T A Nordheim, G H Jones, E Roussos, J S Leisner, A J Coates, W S KurthAbstract:On 26 September 2005, Cassini conducted its only close targeted flyby of Saturn's small, irregularly shaped moon Hyperion. Approximately 6 min before the closest approach, the electron spectrometer (ELS), part of the Cassini Plasma Spectrometer (CAPS) detected a field-aligned electron population originating from the direction of the moon's surface. Plasma Wave activity detected by the Radio and Plasma Wave instrument suggests electron beam activity. A dropout in energetic electrons was observed by both CAPS-ELS and the Magnetospheric Imaging Instrument Low-Energy Magnetospheric Measurement System, indicating that the moon and the spacecraft were magnetically connected when the field-aligned electron population was observed. We show that this constitutes a remote detection of a strongly negative (~ −200 V) surface potential on Hyperion, consistent with the predicted surface potential in regions near the solar terminator.
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characteristics of dust particles detected near saturn s ring plane with the cassini radio and Plasma Wave instrument
Planetary and Space Science, 2006Co-Authors: Z Wang, A M Persoon, D. A. Gurnett, T F Averkamp, W S KurthAbstract:Abstract During the inbound and outbound passes of the Cassini spacecraft through Saturn's ring plane on July 1, 2004, the Radio and Plasma Wave Science (RPWS) instrument detected many small particles striking the spacecraft. When a small particle strikes the spacecraft at a high velocity, it is instantly vaporized and produces a small cloud of Plasma that expands radially outward from the impact site. As the Plasma cloud expands away from the spacecraft it produces a voltage pulse on the RPWS electric field antennas, the amplitude of which is proportional to the mass of the impacting particle. Two types of measurements are made: Waveform measurements from the x-axis dipole antenna, and spectrum measurements from the w-axis monopole antenna. The Waveform measurements from the dipole antenna provide a determination of the impact rate and the relative mass distribution, and the spectrum measurements from the monopole antenna provide a determination of the root-mean-square particle mass. The impact rate at both ring plane crossings provides a good fit to the sum of two Gaussians, with an average impact rate of about 1200 per second (the exact value depends on the voltage threshold used), and a north–south thickness of about 300 km. The mass distribution depends on the distance from the ring plane, varying from about m−2 near the ring plane at z = 0 ± 100 km , where z is the north–south distance from the ring plane, to as steep as m−4 well away from the ring plane at z = 500 ± 100 km . The mechanisms involved in the impact detection are discussed and a formula relating the root-mean-square particle mass to the root-mean-square voltage on the w-axis monopole is derived. Using this formula, the root-mean-square mass is estimated to be 7.7×10−11 g, which for water ice particles with a density of 0.92 g cm−3 gives a root-mean-square radius of about 2.6 μm.