Article
Engineering, Electrical & Electronic
Shuang Pang, Yang Zeng, Qi Yang, Bin Deng, Hongqiang Wang
Summary: This paper proposed a segmented RCS scaling relation for THz RCS scaled measurements, taking into account the randomness of surface roughness. The validity of the new scaling relation has been verified by numerical simulations and measurement experiments, providing references for RCS scaled measurements in the THz spectrum with consideration of surface roughness.
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2021)
Article
Engineering, Multidisciplinary
Wen-Jing Zheng, Zi He, Da-Zhi Ding, Fan Ding, Ru-Shan Chen
Summary: This study introduces an advanced two-scale model for calculating electromagnetic scattering from rough surfaces, showing improved accuracy and consistency across different incident angles. The model is compared with other methods to verify its accuracy.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2022)
Article
Materials Science, Multidisciplinary
Z. S. Gevorkian, L. S. Petrosyan, T. V. Shahbazyan
Summary: We study the impact of light absorption on weakly rough metal surfaces with roughness amplitude and correlation length smaller than the skin depth in metal. By developing a systematic perturbative approach, we find that the variations in roughness-related absorptance are influenced by several system parameters, resulting in greater absorption for smaller roughness amplitudes. We show that for small-scale roughness, the variations in absorptance are primarily caused by an increase in the effective volume of the surface layer induced by roughness, where incident light is mostly absorbed. Furthermore, we argue that these absorptance fluctuations between different samples, while unrelated to any electron scattering processes, can manifest as sample-to-sample variations of the Drude scattering rate reported in recent measurements of the metal dielectric function.
Article
Chemistry, Multidisciplinary
Matin Dehghani, Christin David
Summary: The study investigates the absorption loss in multilayered Ag/ZnO thin films with different surface morphologies using a combination of scattering matrix approach and diffraction theory. The theoretical modeling is in excellent agreement with the experimental measurements, and can be applied to a wide range of wavelengths, surface morphologies, and materials with rough surface textures.
Article
Physics, Applied
Zahra Barani, Kamil Stelmaszczyk, Fariborz Kargar, Yevhen Yashchyshyn, Grzegorz Cywinski, Sergey Rumyantsev, Alexander A. Balandin
Summary: The interaction of terahertz electromagnetic radiation with dilute graphene-epoxy composites was studied experimentally, showing unexpectedly high shielding effectiveness achieved mainly through absorption. The shielding effectiveness increases with frequency, suggesting the potential for practical applications with thin-film or spray coatings of these composites.
APPLIED PHYSICS LETTERS
(2022)
Article
Polymer Science
Matteo Sanviti, Lars Mester, Rainer Hillenbrand, Angel Alegria, DanielE. Martinez-Tong
Summary: In this study, nanostructured conducting PEDOT:PSS thin films were prepared using solvent vapor annealing (SVA) with tetrahydrofuran (THF) as the low boiling point solvent. Atomic Force Microscopy (AFM) was used to observe the development of distinct nanostructures with solvent exposure time. The physical properties of the nanostructures were evaluated through nanomechanical, nanoelectrical, and nanoinfrared (nano-FTIR) measurements. It was demonstrated that exposure to THF can effectively and selectively modify the surface nanostructure of PEDOT:PSS and thus its final properties. The nanoscale studies also provided evidence of molecular rearrangements during nanostructure fabrication, which is crucial for expanding the potential applications of this polymer in thermoelectric and optoelectronic devices.
Article
Multidisciplinary Sciences
Z. Chen, C. B. Curry, R. Zhang, F. Treffert, N. Stojanovic, S. Toleikis, R. Pan, M. Gauthier, E. Zapolnova, L. E. Seipp, A. Weinmann, M. Z. Mo, J. B. Kim, B. B. L. Witte, S. Bajt, S. Usenko, R. Soufli, T. Pardini, S. Hau-Riege, C. Burcklen, J. Schein, R. Redmer, Y. Y. Tsui, B. K. Ofori-Okai, S. H. Glenzer
Summary: By combining free electron laser pulses and terahertz radiation, researchers are able to measure the evolution of electrical conductivity in gold foils under extreme conditions and determine the contributions of electron-electron and electron-ion scattering to the resistivity.
NATURE COMMUNICATIONS
(2021)
Article
Geochemistry & Geophysics
Yunhe Liu, Luyuan Wang, Changchun Yin, Xiuyan Ren, Bo Zhang, Yang Su, Zhihao Rong, Xinpeng Ma
Summary: In this study, a novel three-dimensional (3-D) forward modeling scheme for transient electromagnetic (TEM) waves in rough media is proposed to evaluate the influence of roughness and contribute to data inversion. A fractional-order time derivative is introduced to establish the governing equation for subdiffusion of EM waves in rough media. An unequal step length time discretization method is used to reduce the total number of time steps. Additionally, an implicit time-domain finite-element method using unstructured tetrahedron discretization is adopted, and an efficient time segmentation strategy combined with parallel RHS construction is proposed to accelerate modeling.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Geochemistry & Geophysics
Ahmet Sefer, Ali Yapar
Summary: This article presents a new method for reconstructing the profiles of perfectly electric conducting (PEC) rough surfaces using electromagnetic waves. It introduces two different approaches for reconstruction and provides a comprehensive numerical analysis to demonstrate their feasibility. The results show that both methods can accurately reconstruct rough surfaces.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Review
Chemistry, Multidisciplinary
Qinxi Qiu, Zhiming Huang
Summary: 2D materials are considered promising for photodetectors due to their unique properties, but limitations such as low quantum efficiency, noise, and slow response are caused by their thinness. Current research focuses on improving the performance of 2D material photodetectors, but balancing sensitivity and response speed remains challenging.
ADVANCED MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Mark Wagner, Herbert Groll, Ali Dormiani, Venkatesh Sathyanarayanan, Christoph Mecklenbrauker, Peter Gerstoft
Summary: In this study, phase-coherent measurements of a pilot tone from a DTV station were taken by a 24-element vertical array 168 km away from the transmitter in Southern California over a 15-day period. The analysis of the collected data revealed a correlation between ASNR and atmospheric parameters related to refractivity.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Astronomy & Astrophysics
Pengxiang Xie, Ke Guan, Danping He, Haofan Yi, Jianwu Dou, Zhangdui Zhong
Summary: Terahertz (THz) communications are critical for future wireless communication. This study investigates the scattering propagation characteristics on rough surfaces using a full-wave simulation method. The results show that scattering becomes a significant propagation mechanism with increased roughness, and the depolarization effect is more severe for rougher surfaces. The findings are important for accurate THz channel modeling and the design of THz communication systems.
Article
Geochemistry & Geophysics
Yanmin Zhang, Honglei Zheng, Yunhua Wang, Rui Wang, Lixin Guo
Summary: This article explores a method to remotely measure the thickness of an oil film using terahertz electromagnetic waves, which are more sensitive to oil thickness changes compared to microwave frequencies. By simulating THz EM scattering and analyzing various influences on the normalized radar cross section, the study shows that THz frequencies have the potential to effectively probe oil film thickness.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2021)
Article
Materials Science, Multidisciplinary
Igor V. Antonets, Yevgeny A. Golubev, Vladimir I. Shcheglov
Summary: We present an algorithm for calculating structural characteristics of amorphous nanogranular composites. The algorithm utilizes measured reflection coefficients or conductivity of microwave waves to determine the mean free path of electrons, average sizes of granules, and gaps between them. The algorithm was tested on amorphous granular composite films and the results were validated using atomic force and scanning electron microscopy.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Arka Chaudhuri, Rupali Rakshit, Kazunori Serita, Masayoshi Tonouchi, Kalyan Mandal
Summary: This study successfully synthesized magnetite nanoparticles and nano-hollow spheres of different diameters, which were coated with silica and found to be useful as electromagnetic shielding devices. The detailed morphology and size-dependent terahertz absorption study further supported their potential applications.
IEEE TRANSACTIONS ON MAGNETICS
(2021)