Article
Engineering, Electrical & Electronic
Michael S. Shur
Summary: The terahertz (THz) technology has wide applications, with Beyond 5G Wi-Fi and Internet of Things (IoT) as its expected killer applications. Plasmonic TeraFETs with feature sizes down to 3 nm could enable a dramatic expansion of these applications.
IEEE SENSORS JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Emmanuel K. Ampadu, Jungdong Kim, Eunsoon Oh
Summary: A lateral photovoltaic device was fabricated for infrared to terahertz detection by chemically depositing PbS films on titanium substrates. Material properties of PbS films on glass were discussed, and the device operated at room temperature with a wavelength range up to 50 μm, making it highly applicable in various fields.
Article
Optics
Abdulrahman Mesgin Balow, Mehdi Khatir, Nasrin Amiri
Summary: A novel plasmonic nano-antenna array with stepped strips at the edge of contact electrodes is proposed for improved performance in optical-to-terahertz conversion efficiency. Simulations show that this photoconductive antenna can efficiently transmit light to LT GaAs substrate under an optical pump power of 50 mW without any reflection, generating an optical current of 215 nA and achieving broadband terahertz detection over the 0.1-8 THz frequency range with significant improvement over previous structures.
Article
Materials Science, Multidisciplinary
Xinxin Gao, Bao Jie Chen, Kam-Man Shum, Qian Ma, Wen Yi Cui, Tie Jun Cui, Chi Hou Chan
Summary: The next-generation wireless communications and intrachip and interchip communications require high-speed terahertz (THz) interconnects, which can be achieved using spoof surface plasmon polaritons (SSPPs). This study proposes and experimentally demonstrates planar multifunctional THz plasmonic devices based on the interaction between SSPPs and spoof localized surface plasmon (SLSPs). These devices enable pass-through transmission, multifrequency resonances, and phase shift in THz plasmonic systems, making them promising for on-chip integrations, wireless communications, and sensing systems.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Nanoscience & Nanotechnology
Anqi Yu, Zhenyu Yang, Miao Cai, Huiping Zhang, Zhengan Tian, Xuguang Guo, Lanxia Wang, Alexei Balakin, Alexander P. Shkurinov, YiMing Zhu
Summary: Terahertz detectors based on two-dimensional Dirac materials provide high response and low noise at room temperature. However, their ultrathin nature leads to poor absorption and limited response over a broad frequency range. In this study, metallic gratings are used to enhance the excitation efficiency of graphene plasmons, resulting in terahertz response orthogonal to the polarization of the incidence. The coupling efficiency between graphene plasmons and THz incidence is effectively enhanced, improving absorption and responsivity.
Article
Materials Science, Multidisciplinary
Philipp Karl, Sandra Mennle, Monika Ubl, Mario Hentschel, Philipp Flad, Jing-Wei Yang, Tzu-Yu Peng, Yu-Jung Lu, Harald Giessen
Summary: The development of photon-based technologies such as quantum cryptography and quantum computing relies on high-fidelity and fast photodetectors capable of detecting single photons. Superconducting nanowire single photon detectors, utilizing the superconducting-to-normal conducting phase transition, offer a promising solution. Using resonant plasmonic perfect absorber effects, these detectors can achieve high efficiency, polarization-independent absorption at a specific wavelength. Additionally, the target wavelength can be easily adjusted by modifying the detector's geometry.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Chemistry, Physical
Lorenzo Tesi, Dominik Bloos, Martin Hrton, Adam Benes, Mario Hentschel, Michal Kern, Alisa Leavesley, Rainer Hillenbrand, Vlastimil Krapek, Tomas Sikola, Joris van Slageren
Summary: A new resonator composed of an array of diabolo antennas with a back-reflecting mirror is designed and fabricated to enhance THz magnetic fields in a microscopic volume. Simulations and THz EPR measurements show a 30-fold signal increase for thin film samples, reaching a theoretical value of 7500 for samples confined to the active region of the antennas. These findings open the door to understanding fundamental processes in nanoscale samples, such as junctions in spintronic devices or biological membranes.
Article
Engineering, Electrical & Electronic
Sherin Thomas, Mandeep Singh, M. N. Satyanarayan
Summary: A high sensitivity refractive index SIS waveguide with a ring resonator sensor at THz frequency is proposed in this study. The topological structure of the proposed filter is numerically simulated using the finite element method. By filling the air-filled ring resonator cavity with different refractive index materials, a maximum sensitivity of 0.509 THz/RIU is achieved. The transmission characteristics are studied by varying the structural dimensions, and it is observed that the system can be treated as a frequency selective device.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Organic
Andrea N. Zeppuhar, Daniel E. Falvey
Summary: A visible light absorbing anthraquinone derivative, 1-tosyloxy-2-methoxy-9,10-anthraquinone (QT), can mediate both cationic and radical polymerizations depending on the intensity of visible light used. Under high-intensity irradiation, QT generates acid to catalyze the cationic ring-opening polymerization of lactones, while under low-intensity conditions, QT photooxidizes DMSO to generate methyl radicals for the RAFT polymerization of acrylates. This dual capability allows for switching between radical and cationic polymerizations in a one-pot synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Physics, Multidisciplinary
P. Sai, V. V. Korotyeyev, M. Dub, M. Slowikowski, M. Filipiak, D. B. But, Yu. Ivonyak, M. Sakowicz, Yu. M. Lyaschuk, S. M. Kukhtaruk, G. Cywinski, W. Knap
Summary: In this study, we investigated resonant two-dimensional plasmon excitations in grating-gated quantum well heterostructures, which allows for electrical control of charge carrier density. Our results show that all terahertz plasmonic resonances in these structures can be explained within the plasmonic crystal model, and we identified two different plasmonic crystal phases. By gate controlling the modulation degree, we observed a continuous transition between these phases. We also discovered that the resonant plasma frequencies of ungated regions still depend on the gate voltage. These findings have implications for understanding THz plasma physics and developing all-electrically tunable devices for THz optoelectronics.
Article
Engineering, Electrical & Electronic
E-San Jang, Min Woo Ryu, Ramesh Patel, Sang Hyo Ahn, Ki Jin Han, Kyung Rok Kim
Summary: A compact monolithic trantenna device was developed for high-performance sub-THz wave detection, achieving significant enhancement in photoresponse by changing the ground source location and scaling down the inner contact diameter. The experiment also demonstrated a record-high free-space responsivity and reduced noise equivalent power for the plasmonic wave nano-ring FET without external gain.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Optics
Xinyu Ma, Yanfeng Li, Jiaguang Han
Summary: An ultracompact terahertz mode division multiplexer based on THz spoof SPPs is proposed. The mode multiplexer can be designed with a reduced footprint by exploiting more degrees of freedom in the parameters of the unit cell. It can simultaneously support the propagation of four mode channels: TM0, TM1, TM2, and TM3 modes.
Review
Nanoscience & Nanotechnology
Taiichi Otsuji, Stephane Albon Boubanga-Tombet, Akira Satou, Deepika Yadav, Hirokazu Fukidome, Takayuki Watanabe, Tetsuya Suemitsu, Alexander A. Dubinov, Vyacheslav V. Popov, Wojciech Knap, Valentin Kachorovskii, Koichi Narahara, Maxim Ryzhii, Vladimir Mitin, Michael S. Shur, Victor Ryzhii
Summary: This paper reviews recent advancements in graphene-based plasmonic metamaterials for terahertz (THz) laser transistors. The researchers investigate various approaches using graphene plasmonic metamaterials to achieve room-temperature, dry-cell-battery operated intense THz lasing with fast direct modulation. The paper discusses device structures and design constraints for coherent light sources applicable to future THz wireless communication systems.
Article
Engineering, Electrical & Electronic
Tong Li, Hang Chen, Fengqiang Zhang, Jia Zhang, Zhenlong Wang
Summary: This paper presents the design of a three-layered structure metamaterial for an ultra-broadband terahertz absorber. The absorber achieves high absorption rates over a wide frequency range and is insensitive to different polarization modes, which is significant for practical applications.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Physics, Applied
Kevin Froberger, Benjamin Walter, Melanie Lavancier, Romain Peretti, Guillaume Ducournau, Jean-Francois Lampin, Marc Faucher, Stefano Barbieri
Summary: The study introduces a micro-mechanical terahertz detector fabricated on a silicon on insulator substrate, operating at room temperature. It achieves a high responsivity with a broad frequency response and fast thermal response time.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Victor Ryzhii, Maxim Ryzhii, Akira Satou, Vladimir Mitin, Michael S. Shur, Taiichi Otsuji
Summary: The injection of ballistic electrons can lead to terahertz radiation and be utilized for optimizing devices through effective Coulomb drag and plasma instability.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2022)
Review
Nanoscience & Nanotechnology
Taiichi Otsuji, Stephane Albon Boubanga-Tombet, Akira Satou, Deepika Yadav, Hirokazu Fukidome, Takayuki Watanabe, Tetsuya Suemitsu, Alexander A. Dubinov, Vyacheslav V. Popov, Wojciech Knap, Valentin Kachorovskii, Koichi Narahara, Maxim Ryzhii, Vladimir Mitin, Michael S. Shur, Victor Ryzhii
Summary: This paper reviews recent advancements in graphene-based plasmonic metamaterials for terahertz (THz) laser transistors. The researchers investigate various approaches using graphene plasmonic metamaterials to achieve room-temperature, dry-cell-battery operated intense THz lasing with fast direct modulation. The paper discusses device structures and design constraints for coherent light sources applicable to future THz wireless communication systems.
Article
Physics, Applied
M. Ryzhii, V Ryzhii, T. Otsuji, V Mitin, M. S. Shur
Summary: The response of lateral n(+)-i-n-n(+) graphene field-effect transistors (GFETs) to terahertz (THz) radiation is analyzed in this study. The nonlinearity caused by Coulomb drag and plasmonic oscillations in the GFET channel enables a resonantly strong response, which can be used for effective resonant detection of THz radiation.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Biomedical
Michael Shur, Outman Akouissi, Olivier Rizzo, Didier J. Colin, John M. Kolinski, Stephanie P. Lacour
Summary: The study proposes a simple fabrication and processing sequence to deliver brain-like hydrogel implants into the nervous tissue. Real-time monitoring of hydrogel re-swelling kinetics in vivo is achieved using microcomputed tomography, and the study reveals how implant geometry and mechanical interplay govern in vivo buckling. These findings provide important guidance for the engineering of biomimetic brain implants.
Article
Physics, Applied
V. Ryzhii, C. Tang, T. Otsuji, M. Ryzhii, V. Mitin, M. S. Shur
Summary: We evaluated THz detectors based on graphene channel (GC) and a floating metal gate (MG) separated from GC by a black-phosphorus (b-P) or black-arsenic (b-As) barrier layer (BL). The operation of these GC-FETs involves heating of the two-dimensional electron gas in GC by THz radiation, leading to thermionic emission of hot electrons from GC to MG. This results in variation of the floating gate potential, affecting the source-drain current. At THz radiation frequencies close to plasmonic resonance frequencies in the gated GC, the variation in source-drain current and detector responsivity can be resonantly large.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
M. S. Shur, X. Liu, T. Ytterdal
Summary: Novel metal oxide materials and improved fabrication processes have significantly enhanced the performance of thin film transistor (TFT), with approaches of 150 cm²/Vs in the effective field-effect mobility. An improved compact TFT model based on three models has been reported in this study, which considers the non-exponential slope in the subthreshold regime and the non-trivial capacitance dependence on gate bias. The TFTs have shown a substantial response to impinging THz and sub-THz radiation, and the detection sensitivity can be improved by using a complementary inverter and phase-matched THz signal feeding.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2023)
Review
Physics, Applied
V. Ryzhii, C. Tang, T. Otsuji, M. Ryzhii, V. Mitin, M. S. Shur
Summary: This article analyzes the operation of terahertz (THz) bolometric detectors based on field-effect transistor (FET) structures with graphene channels (GCs) and black-phosphorus and black-arsenic gate barrier layers (BLs). The detectors utilize the heating of a two-dimensional electron gas (2DEG) by THz radiation, leading to the emission of hot electrons into the gate via the BL. The excitation of plasmonic oscillations in the GC by THz signals results in a resonant detector response and increased responsivity.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Applied
Babak Nikoobakht, Yuqin Zong, Okan Koksal, Amit Agrawal, Christopher Montgomery, Jaime Rumsey, Jacob Leach, Michael Shur
Summary: In this study, we investigate the impact of the fin aspect ratio on the external quantum efficiency (EQE) and UV emission of AlGaN fin/p-GaN heterojunctions. With decreasing aspect ratio, the UV emission of the fins increases and EQE is enhanced by 7 times. This can be attributed to the conservation of the volume of the carrier depletion region within a fin.
APPLIED PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
V. Ryzhii, C. Tang, T. Otsuji, M. Ryzhii, S. G. Kalenkov, V. Mitin, M. S. Shur
Summary: In this study, we investigate the response of the micromechanical field-effect transistors (MMFETs) to terahertz (THz) signals. The MMFET utilizes microcantilevers (MC) as a floating gate and the movable mirror of Michelson optical interferometer. The mechanical vibrations of MC are converted into optical signals, allowing MMFET to operate as a THz radiation detector. The combination of mechanical and plasmonic resonances in MMFET, along with optical amplification, enables effective THz detection.
Article
Physics, Multidisciplinary
Yuhui Zhang, Michael Shur
Summary: We demonstrate that a periodic multi-grated-gate structure can be used in THz plasmonic FETs (TeraFETs) to enhance THz detection sensitivity. By introducing spatial non-uniformity through separated gate sections, regions with different carrier concentrations and velocities are created, resulting in harmonic behaviors. The frequency spectrum of the DC voltage response consists of enhanced and suppressed regions. In the enhanced region, the response voltage amplitude can be increased up to approximately 100% compared to a uniform channel device. The distribution pattern of these regions is directly related to the number of gate sections (N (s)). A mapping of response amplitude in an N (s)-frequency scale is created, which aids in distinguishing enhanced/suppressed regions and locating optimal operating parameters.
FRONTIERS IN PHYSICS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Muhammad Mahmudul Hasan, Yuhiu Zhang, Nezih Pala, Michael Shur
Summary: p-diamond is a strong candidate for sub-THz and THz applications due to its favorable properties, such as large hole effective mass, high optical phonon energy, high momentum relaxation time, and high mobility. Recent research on p-diamond TeraFETs has shown their potential for sub-THz and THz radiation detection and transmission. N-diamond TeraFETs also hold promise for emerging terahertz applications. One of the main factors affecting plasma wave dampening in our study is the viscosity of the charge carrier medium in the channel.
2023 IEEE 16TH DALLAS CIRCUITS AND SYSTEMS CONFERENCE, DCAS
(2023)
Article
Materials Science, Multidisciplinary
E. Monch, S. O. Potashin, K. Lindner, I. Yahniuk, L. E. Golub, V. Yu. Kachorovskii, V. V. Bel'kov, R. Huber, K. Watanabe, T. Taniguchi, J. Eroms, D. Weiss, S. D. Ganichev
Summary: We present a study on the conversion of terahertz radiation into a dc current in spatially modulated bilayer graphene, tunable by magnetic field and gate voltage. We observe a sharp cyclotron resonance in the photocurrent and discover two effects caused by electron-electron interaction: the splitting of the resonance due to Coulomb coupling and the suppression of its second harmonic due to interparticle collisions. A theoretical model that fits the experimental data perfectly is developed, suggesting that the ratchet current is generated in the hydrodynamic regime of nonideal electron liquid.
Proceedings Paper
Engineering, Biomedical
Michael Shur
Summary: Terahertz radiation is used for detection, sensing, and imaging of biological objects, especially in cancer diagnostics. This technology allows for more accurate cancer detection based on the magnitude and phase information of the THz signal.
ADVANCES IN TERAHERTZ BIOMEDICAL IMAGING AND SPECTROSCOPY
(2022)
Proceedings Paper
Engineering, Biomedical
Taiichi Otsuji, Victor Ryzhii, Michael Shur
Summary: This paper reviews the development of graphene plasmonic THz technology and suggests the potential for commercial applications. The unique properties of graphene and its ability to form heterostructures with other materials make it a promising candidate for revolutionizing THz technology.
ADVANCES IN TERAHERTZ BIOMEDICAL IMAGING AND SPECTROSCOPY
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Michael Shur, Xueqing Liu, Trond Ytterdal
Summary: Short channel Si CMOS is used in THz detectors and THz imaging arrays. The excitation of phase-shifted resonant or overdamped plasma waves enables the operation of TeraFETs as THz spectrometers. Future developments in Si CMOS sub-THz and THz applications will involve Si CMOS integrated circuits such as line-of-sight detectors, traveling wave sub-THz amplifiers, and frequency-to-digital converters.
TERAHERTZ, RF, MILLIMETER, AND SUBMILLIMETER-WAVE TECHNOLOGY AND APPLICATIONS XV
(2022)
