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
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
Engineering, Electrical & Electronic
Yunzhi Gu, Xiang Yao, Huaxiu Geng, Mengying Long, Guijian Guan, Minglie Hu, Mingyong Han
Summary: Metal halides possess the potential for fabricating photothermoelectric detectors due to their unique properties. In this study, a PTE-based detector was successfully fabricated using a lead-free Cs3Cu2I5 nanolayered film. The self-powered detector exhibited light response wavelengths ranging from visible to terahertz. Furthermore, the Cs3Cu2I5 film-based PTE photodetector arrays were successfully applied in flexible imaging. These findings highlight the promise of lead-free Cs3Cu2I5 as a flexible and self-powered ultra-broadband photodetector.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
T. J. Sanders, J. L. Allen, J. Horvat, R. A. Lewis
Summary: The terahertz (THz) spectrum of DL-alanine has been measured for the first time at cryogenic temperatures and with a pure sample. Temperature dependent spectra revealed redshifting, with increasing temperature, for the modes. The study suggests that molecular vibrations of DL-alanine are influenced by temperature and exhibit frequency shifts.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Wendao Xu, Wenzhang Fang, Teng Shi, Xin Ming, Yingli Wang, Lijuan Xie, Li Peng, Hou-Tong Chen, Yibin Ying
Summary: Researchers have developed an alternative approach to achieve tunable terahertz photonic devices by postprocessing nanothickness graphene films. These films have widely tunable conductivity and enable versatile THz applications, such as high-performance electronics, photonics, and sensors. The researchers successfully detected diphenylamine using this method, demonstrating its potential in molecular sensing.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Antton Babaze, Tomas Neuman, Ruben Esteban, Javier Aizpurua, Andrei G. Borisov
Summary: The surface-response formalism (SRF) incorporates quantum surface-response corrections into classical electromagnetic theory via Feibelman parameters, providing a way to study quantum effects in the optical response of metallic nanostructures. However, the current method neglects the nonlocality of the optical response parallel to the metal-dielectric interface, which limits its applicability to systems with extreme field confinement. To address this limitation, a dispersive SRF based on a generalized Feibelman parameter is introduced, which correctly describes the plasmonic response of planar and nonplanar systems with extreme field confinement. This work significantly extends the applicability range of the SRF and contributes to the development of computationally efficient semiclassical descriptions of light-matter interaction that capture quantum effects.
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
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
Eleonore Roussel, Christophe Szwaj, Clement Evain, Bernd Steffen, Christopher Gerth, Bahram Jalali, Serge Bielawski
Summary: Recording electric field evolution in single-shot with THz bandwidth is of great importance in various scientific fields. This study introduces a new spectral decoding technique that enables the recording and analysis of THz waveforms with unprecedented resolution over a long time window. Experimental results demonstrate the potential of this technique in accelerator physics and other applications.
LIGHT-SCIENCE & APPLICATIONS
(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
Xinyu Ma, Yanfeng Li, Quan Xu, Jiaguang Han
Summary: A three-channel wavelength division multiplexer based on a terahertz spoof surface plasmon polariton waveguide is designed in this work, which can be used in large-capacity and fast data-transmission communication systems. The multiplexer consists of three cascaded directional couplers and whispering gallery mode resonators, while the plasmonic waveguide is based on periodic metallic pillars with variable parameters. The coupling efficiency between a ring resonator and the straight waveguide can be physically predicted by the coupled mode theory. After further optimization, the three-channel wavelength division multiplexer operates with a low insertion loss of 1.4 dB and a low crosstalk of -16 dB within the frequency range of 0.65-0.69 THz. This device may have important applications in future on-chip terahertz communication systems.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
Gregory S. Bentsen, Subhayan Sahu, Brian Swingle
Summary: Competition between unitary dynamics and local measurements in quantum entanglement phase transition is studied using an analytically tractable circuit model. It is found that the measurement rate affects the entanglement preservation in the hybrid system. The second-order phase transition below a critical measurement rate is characterized by a mean-field-like behavior and described in terms of a simple Ising field theory in 0 + 1 dimensions. The study also relates the results to quantum error correction and discusses the experimental feasibility of simulating the averaged purity.
Article
Chemistry, Analytical
Eugene Soh Jia Hao, Nan Zhang, Qiang Zhu, Xizu Wang, Karen Ke Lin
Summary: This research uses terahertz attenuated total reflection spectroscopy and hybrid graphene oxide and carbon nanotube thin-film sensors to obtain distinct spectral signals in commercial eye drops. The results provide a solid foundation for the future analysis and quality detection of eye drops.
Article
Physics, Applied
A. V. Bogatskaya, N. V. Klenov, P. M. Nikiforova, A. M. Popov, A. E. Schegolev
Summary: The article discusses the use of a heterostructure made of doped and undoped semiconductor layers to detect broadband terahertz radiation. By adjusting the thickness and doping levels of the layers, it is possible to detect pulses in the range of frequencies greater than 10^12 Hz with a spectral width on the order of the carrier frequency.
TECHNICAL PHYSICS LETTERS
(2021)
Article
Materials Science, Ceramics
Xinxi Zeng, Yuhe Liang, Han Zhang, Xiaoqing Xi, Jianguo Cao, Bo Li, Ji Zhou
Summary: A numerical smoothing method using B-spline algorithm was introduced to denoise the THz responses of rare-earth orthoferrites, showing more stability and effectiveness in noise reduction compared to the traditional Savitzky-Golay smoothing method. This approach may offer a promising way to reduce noise in the intrinsic but weak resonances of these materials.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
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
Physics, Applied
John Chilleri, Poppy Siddiqua, Michael S. Shur, Stephen K. O'Leary
Summary: Drawing on a collection of electron transport results and other material parameters, this study establishes the upper limits of device performance for zinc blende boron-nitride-based electron devices. It explores how device performance varies with device length-scale and compares results with other materials. The study focuses on effective mobility and cutoff frequency as key performance metrics.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
G. R. Aizin, J. Mikalopas, M. Shur
Summary: Circularly polarized electromagnetic waves generate a circulating DC plasmonic current on a conducting ring, leading to an inverse Faraday effect in nanorings. By modulating the width of the ring, a large-scale inverse Faraday effect can be achieved.
Article
Chemistry, Multidisciplinary
Xueqing Liu, Trond Ytterdal, Michael Shur
Summary: This paper presents an update of the RPI thin-film transistor (TFT) compact model, which accurately describes the gate voltage-dependent channel layer thickness and allows for terahertz frequency simulations. The model introduces two subthreshold ideality factors to control the gate voltage and its effect on the current and capacitance. The updated model reproduces the conventional model at low frequencies, fits measured data accurately, and extends the application of the model to the terahertz frequency range.
Article
Chemistry, Physical
Babak Nikoobakht, Jonathan Lee, Amit Agrawal, Scott Wight, Michael Shur
Summary: Nanostructured semiconductors have the potential to miniaturize electrically driven semiconductor lasers. This study analyzes lateral ZnO fins as an optical gain medium and an optical resonator, revealing their excellent performance in electron-hole pair collection efficiency and resonance mode formation.
JOURNAL OF PHYSICAL CHEMISTRY C
(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)