Article
Physics, Condensed Matter
A. T. Apostolov, I. N. Apostolova, J. M. Wesselinowa
Summary: The multiferroic properties of GaV4S8, recently observed experimentally, were studied using a microscopic model and Green's function technique. The polarization P saturates at low temperatures and increases at higher temperatures, reaching a maximum around 13 K before decreasing near the phase transition temperature. The specific heat and phonon energy also show variations with temperature and magnetic field values.
SOLID STATE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Clemens Vittmann, James Lim, Dario Tamascelli, Susana F. Huelga, Martin B. Plenio
Summary: This study examines the role of delocalized phonon modes in electron transport in chiral structures and demonstrates that spin selectivity can originate from spin-dependent energy and momentum conservation in electron-phonon scattering events. The degree of spin polarization, however, depends on environmental factors and the presence of external driving fields. The parametric dependence allows for experimentally testable predictions of the model.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Xiao Wan, Dengke Ma, Dongkai Pan, Lina Yang, Nuo Yang
Summary: In this study, phonon transport optimization in graphene nanoribbon was achieved by designing nanopillared nanostructures based on resonance hybridization. It was found that thermal conductance decreases non-monotonically with an increase in the number of nanopillared structures, blocking phonon transport. Insights into controlling phonon transport in nanostructures were provided through mode-analysis, calculations, and simulations.
MATERIALS TODAY PHYSICS
(2021)
Article
Physics, Applied
Dusan I. Ilic, Jovan P. Setrajcic, Stevo K. Jacimovski, Sinisa M. Vucenovic
Summary: This paper investigates the influence of phonon quasiparticle subsystem on the thermal capacitance of a two-dimensional quasicrystal ultrathin film and derives an exact formula for the thermal capacitance of an ideal ultrathin film valid over the entire temperature range. The obtained formula is compared with corresponding graphs of massive crystalline structures in both low-temperature and high-temperature regions, and the conclusions are highly consistent with recent results related to the possibility of high-temperature superconductivity.
MODERN PHYSICS LETTERS B
(2023)
Article
Physics, Multidisciplinary
M. Amir Bazrafshan, Farhad Khoeini
Summary: In this study, a phosphorene nanodisk connected to two zigzag phosphorene nanoribbons is numerically investigated. The change in structure from a ribbon to a disk creates an energy gap and increases the maximum Seebeck coefficient. The electric fields can also control the electron transmission and Seebeck coefficients, with the transverse electric field having a stronger effect.
FRONTIERS IN PHYSICS
(2023)
Review
Physics, Condensed Matter
Yu-Jia Zeng, Zhong-Ke Ding, Hui Pan, Ye-Xin Feng, Ke-Qiu Chen
Summary: The phonon heat transport property in quantum devices has been of great interest due to its significant quantum behaviors. Efforts have been made in establishing theoretical methods for phonon heat transport simulation in nanostructures, with challenges remaining in modeling phonon heat transport from wavelike coherent regime to particlelike incoherent regime. Among various theoretical approaches, Non-equilibrium Green's function (NEGF) method has attracted wide attention for its ability to perform full quantum simulation.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Nanoscience & Nanotechnology
Hamilton Carrillo-Nunez, Cristina Medina-Bailon, Vihar P. Georgiev, Asen Asenov
Summary: In this study, full-band quantum transport simulations were conducted on a device with hole-phonon interactions, consisting of two gates-all-around and a p-type Si nanowire channel. The self-energy expression for hole-phonon interaction within the mode-space representation is introduced using the six-band k·p method.
Article
Crystallography
Guangfang Li, Lianhe Li
Summary: This paper considers the Eshelby tensor for two-dimensional piezoelectric quasicrystal composites, providing explicit expressions using both the Green's function method and the interior polarization tensor method. Numerical examples of the Eshelby tensor for 2D piezoelectric QCs with ellipsoidal inclusions are also discussed in detail.
Article
Chemistry, Multidisciplinary
Jens Sonntag, Sven Reichardt, Bernd Beschoten, Christoph Stampfer
Summary: Researchers have investigated the tunability of phonon polarization in suspended uniaxially strained graphene using magneto-phonon resonances, achieving electrostatic control over the phonon polarization and paving the way for phononic applications.
Article
Chemistry, Multidisciplinary
Hans Jurgen von Bardeleben, Jean-Louis Cantin, Uwe Gerstmann, Wolf Gero Schmidt, Timur Biktagirov
Summary: The nitrogen-vacancy (NV) center in 3C-SiC, akin to the NV center in diamond, has competitive properties and significant technological advantages for qubit applications. Its strong variation of the zero-field splitting also allows for nanoscale thermal sensing applications.
Article
Engineering, Electrical & Electronic
A. M'foukh, J. Saint-Martin, P. Dollfus, M. Pala
Summary: In this work, the authors present a first-principles study of quantum transport in tunnel FETs based on van der Waals heterostructures of transition metal dichalcogenides (TMDs). The results show that vdW tunnel FETs are highly sensitive to the phonon coupling due to polar optical phonons present in TMDs, resulting in an increased sub-threshold swing and reduced ON-current. However, vdW TFETs are still able to provide high ON-current values due to the inversion of CB and VB at high V-GS and high inter-valley tunneling.
SOLID-STATE ELECTRONICS
(2022)
Article
Optics
Sergey Korkin, Alexei Lyapustin
Summary: In passive satellite remote sensing, separating the path radiance and surface reflection is still a significant challenge. This paper uses a known radiative transfer technique and a modified code to simulate the interaction between the atmosphere and surface reflection. By combining surface matrices and precomputed output results, the atmospheric correction is achieved and tested against published benchmarks.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2023)
Article
Multidisciplinary Sciences
Zhe Cheng, Ruiyang Li, Xingxu Yan, Glenn Jernigan, Jingjing Shi, Michael E. Liao, Nicholas J. Hines, Chaitanya A. Gadre, Juan Carlos Idrobo, Eungkyu Lee, Karl D. Hobart, Mark S. Goorsky, Xiaoqing Pan, Tengfei Luo, Samuel Graham
Summary: Localized interfacial phonon modes have been observed at a high-quality epitaxial Si-Ge interface at around 12 THz, which significantly contribute to the total thermal boundary conductance. Through molecular dynamics simulations and experimental validation, the impact of these interfacial phonon modes on total thermal boundary conductance has been revealed.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Duk Hyun Lee, Sang-Jun Choi, Hakseong Kim, Yong-Sung Kim, Suyong Jung
Summary: Electron-phonon scatterings play a significant role in determining key physical quantities in solid-state systems. In this study, the authors probe momentum-conserving single- and two-phonon electron-phonon scattering events involving up to eight individual phonon modes in 2D semiconductors, revealing the important influence of different phonon modes on quantum charge flows.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Xiao Dong, Yuan Li, Tianxing Wang, Yipeng An, Yongyong Wang
Summary: The critical conditions of the insulator-to-metal transition in two types of Si-based intermediate-band materials were studied using molecular dynamics simulations and Landauer transmission calculations. It was found that the I-M transition of the substitutional configuration of S occurred when the filled intermediate band expanded and merged with the conduction band, in line with the Mott transition theory. On the other hand, for the substitutional configuration of N, which can be regarded as a standard intermediate-band material, the I-M transition occurred when the partially-filled intermediate band expanded and the carrier localization in the band weakened. The metallic state of the intermediate-band material exhibited some semiconductor properties at low temperature.
NEW JOURNAL OF PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Drake Austin, Kimberly Gliebe, Christopher Muratore, Bryce Boyer, Timothy S. Fisher, Lucas K. Beagle, Anna Benton, Paige Look, David Moore, Emilie Ringe, Benjamin Treml, Ali Jawaid, Richard Vaia, W. Joshua Kennedy, Philip Buskohl, Nicholas R. Glavin
Summary: Electronic circuits, vital for modern electronic devices, require precise integration of conducting, insulating, and semiconducting materials to control electric current flow. A transformative manufacturing approach using laser processing enables direct realization of different material phases within a thin film, resulting in electronic devices with conducting, insulating, and semiconducting properties.
Article
Thermodynamics
Marc Hodes, Ravi Mahajan, Zvi Ruder, Terry Simon, Karl Geisler, Michael Ohadi, Joseph Maurer, David Altman, Jim Wilson, Gennady Ziskind, Mark Spector, Ivan Catton, Vijay Dhir, Timothy Fisher, Portonovo Ayyaswamy, Boravoje Mikic
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
(2021)
Article
Energy & Fuels
Mostafa Abuseada, Chuyu Wei, R. Mitchell Spearrin, Timothy S. Fisher
Summary: We report a process that converts methane to high-value graphitic carbon and hydrogen gas using simulated solar irradiation. The process involves capturing solid carbon in an easily extractable form through localized solar heating, while maintaining active deposition site density until flow is blocked. This method achieves high methane conversion and hydrogen yield.
Article
Thermodynamics
Akshay Bharadwaj Krishna, Kaiyuan Jin, Portonovo S. Ayyaswamy, Ivan Catton, Timothy S. Fisher
Summary: Heat exchangers are essential in supercritical CO2 Brayton cycles for waste heat recovery. These cycles operate at high temperatures and pressures to achieve higher energy density and thermal efficiency. Accurate estimation of heat exchanger performance is crucial for the design and optimization of sCO2 systems.
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
(2022)
Article
Thermodynamics
Akshay Bharadwaj Krishna, Kaiyuan Jin, Portonovo S. Ayyaswamy, Ivan Catton, Timothy S. Fisher
Summary: This paper focuses on the performance modeling and correlations of heat exchangers in high-temperature supercritical CO2 Brayton cycles. The developed correlations for heat transfer and friction characteristics offer superior accuracy and versatility. The study validates the correlations using experimental and computational fluid dynamics data and demonstrates their applicability to supercritical CO2 heat exchangers.
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
(2022)
Article
Thermodynamics
Yuan Hu, Mostafa Abuseada, Abdalla Alghfeli, Saurin Holdheim, Timothy S. Fisher
Summary: This study presents a method for measuring the thermal diffusivity of thin disk samples at high temperatures using a modified angstrom ngstrom's method, along with nondestructive temperature measurements using an infrared camera. The results demonstrate excellent agreement with reference values obtained by other methods, validating the accuracy of the proposed method.
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
(2022)
Article
Physics, Fluids & Plasmas
Majed A. Alrefae, Gayathri Shivkumar, Alina A. Alexeenko, Sergey O. Macheret, Timothy S. Fisher
Summary: In this study, nanocrystalline graphitic films were successfully deposited on Cu foil in a roll-to-roll plasma-enhanced chemical vapor deposition system. The influence of discharge modes on the synthesis of graphitic films was investigated, and electrical and spectroscopic characterizations supported with modeling were performed. It was found that by adjusting the discharge modes, different qualities of nanocrystalline graphitic films could be produced without supplemental heating.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2022)
Article
Instruments & Instrumentation
Abuseada Mostafa, Alghfeli Abdalla, Timothy S. Fisher
Summary: The paper presents a method for characterizing the output radiative flux of a solar simulator using an inverse mapping technique and custom instruments. This method allows for practical characterization of solar irradiation and provides a cost-effective means of monitoring the performance of solar sources over time.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Correction
Instruments & Instrumentation
Mostafa Abuseada, Abdalla Alghfeli, Timothy S. Fisher
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Materials Science, Multidisciplinary
Mostafa Abuseada, Abdalla Alghfeli, Timothy S. Fisher
Summary: This paper introduces a method to enhance heat spreading capabilities by synthesizing thin graphitic layers on organic substrates through a vacuum deposition process. The use of a light source that can be replaced with solar power enables rapid heating and improves growth rates over larger areas compared to laser processing, mitigating the issue of porosity in graphitic layers. Analysis of the enhanced organic substrates confirms graphitic conversion.
Article
Engineering, Electrical & Electronic
Abdalla Alghfeli, Mostafa Abuseada, Timothy S. Fisher
Summary: This study explores the use of solar-thermal energy to reduce greenhouse gas emissions in industrial processes. Through a solar simulator and a chemical vapor deposition system, high-quality graphene films are synthesized automatically. The results demonstrate the ability of the system to produce high-value products directly from renewable energy sources, and with process control and automation.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
(2022)
Article
Chemistry, Physical
Mostafa Abuseada, R. Mitchell Spearrin, Timothy S. Fisher
Summary: This article introduces a new solar-thermal methane pyrolysis process that produces hydrogen gas and high-value graphitic carbon product in a fibrous carbon medium. The process reaches steady-state operation quickly and the graphitic product can be easily extracted from the solar reactor.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Multidisciplinary
Yuan Hu, Mostafa Abuseada, Abdalla Alghfeli, Saurin Holdheim, Timothy S. Fisher
Summary: This study proposes a Bayesian analysis method that uses a parametric surrogate model in the form of polynomial chaos to accelerate the thermal diffusivity physical model for high-temperature determination. The No-U-Turn sampler is employed to improve the efficiency of the MCMC sampler.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Energy & Fuels
Mostafa Abuseada, Timothy S. Fisher
Summary: This study presents a scalable route for continuous solar-thermal methane pyrolysis, using a roll-to-roll mode of operation with a fibrous carbon substrate. It converts natural gas into hydrogen and high-quality carbon product with virtually no CO2 emission, offering a promising solution to decarbonize fossil fuels.
Proceedings Paper
Thermodynamics
Ujash Shah, Subramanian S. Iyer, Timothy S. Fisher
Summary: Wafer-scale systems utilize Silicon Interconnect Fabric to achieve high package density and peak heat flux density up to 3 W/mm(2). System requirements vary based on heterogeneous components, with estimated total power delivery of 40 kW and average heat flux density of 1 W/mm(2). Flash cooling enables segmented thermal management with peak heat transfer coefficients of 50,000 W/m(2)K, allowing zonal arrangement of heterogenous dielets.
PROCEEDINGS OF THE TWENTIETH INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS (ITHERM 2021)
(2021)
