International Journal of Physics | Vol. 12, No. 3, March 2021 | pp. 17–24
DOI: 10.46882/2021/IJP/000131
Research Article
Title: Thermal Dispersion Metrics and Phonon Wavepacket Scattering Dynamics across Graphene-Boron Nitride Junctions
Names of Authors: D. W. Meyer¹, J. R. Weber²
Authors’ Affiliations:
¹ Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany
² Physik-Department, Technische Universität München, Garching, Germany
Abstract: Maximising thermal dissipation metrics across low-dimensional heterostructures is an engineering priority for managing hotspots inside next-generation high-frequency field-effect transistors and optoelectronic microchips. This paper details molecular dynamics simulations aimed at quantifying thermal dispersion parameters and mapping acoustic phonon wavepacket scattering dynamics across graphene-boron nitride (Gr-hBN) lateral junctions. Atomistic lattices were constructed with the optimized Tersoff empirical potentials, containing varying structural configurations of boundary mismatch lines and localized point vacancy defects. Longitudinal and transverse acoustic phonon wavepackets were launched across a high-frequency grid centered between 2.0 THz and 12.0 THz. The computational models prove that high-frequency acoustic phonons (f greater than 6.0 THz) face severe diffuse scattering patterns at defective junction planes, dropping the calculated transmission coefficient from 0.78 down to 0.16. This thermal resistance stems from localized strain profiles and interface-confined vibrational resonance modes. The composite interface thermal conductance fell by 52.0% when boundary defect percentages were adjusted from 1.0% to 5.0% at 300.0 K, revealing atomic constraints for nanoscale heat management.
Keywords: Thermal conductance; phonon wavepacket; molecular dynamics; interface defects; graphene; boron nitride
Manuscript Timeline: Received: December 14, 2020; Revised: January 20, 2021; Accepted: February 08, 2021; Published: March 15, 2021
Citation: Meyer, D. W., & Weber, J. R. (2021). Thermal Dispersion Metrics and Phonon Wavepacket Scattering Dynamics across Graphene-Boron Nitride Junctions. International Journal of Physics, 12(3), 17–24.
International Journal of Physics | Vol. 12, No. 2, February 2021 | pp. 9–16
DOI: 10.46882/2021/IJP/000130
Research Article
Title: Relativistic Hydrodynamic Modeling of Collective Elliptic Flow Fluctuations in Asymmetric Neon-Gold Collisions
Names of Authors: S. C. O’Brien¹, L. M. Dupont²
Authors’ Affiliations:
¹ School of Physics, University College Dublin, Dublin, Ireland
² Laboratoire de Geologie de Lyon, Ecole Normale Superieure de Lyon, Lyon, France
Abstract: High-energy asymmetric heavy-ion interactions generate miniature high-density subatomic interaction volumes that allow researchers to map out the minimal spatial boundaries required to establish liquid-like quark-gluon plasma states. This paper implements a relativistic hydrodynamic modeling framework to simulate multi-particle production cascades and measure elliptic flow fluctuations during asymmetric neon-gold (Ne-Au) collision events. We carried out numerical runs using a 3+1 dimensional viscous hydrodynamic code matched to a statistical hadronization processing module to evaluate final-state momentum metrics. The initial geometric configurations were derived via a Monte Carlo Glauber scheme to capture localized sub-nucleon density fluctuations. The simulations demonstrate that the high-acceleration expansion profile builds a large radial flow signature, boosting the average transverse momentum parameters of emerging kaons up to 1.15 GeV/c in central runs. The simulated elliptic flow index (v²) showcases a clear mass-ordering trend, matching tracking statistics compiled by heavy-ion detectors within a tight ±5.2% accuracy margin. This behavior proves that intermediate asymmetric collision tracks can support brief, fluid-like collective hydrodynamic expansions.
Keywords: Relativistic hydrodynamics; quark-gluon plasma; elliptic flow; asymmetric collisions; Glauber model; statistical hadronization
Manuscript Timeline: Received: November 02, 2020; Revised: December 18, 2020; Accepted: January 11, 2021; Published: February 12, 2021
Citation: O’Brien, S. C., & Dupont, L. M. (2021). Relativistic Hydrodynamic Modeling of Collective Elliptic Flow Fluctuations in Asymmetric Neon-Gold Collisions. International Journal of Physics, 12(2), 9–16.
International Journal of Physics | Vol. 12, No. 1, January 2021 | pp. 1–8
DOI: 10.46882/2021/IJP/000129
Research Article
Title: Kinetic Characterisation of Electron Transport Swarms and Dissociation Kinetics in Ammonia-Hydrogen Plasmas
Names of Authors: D. L. Santos¹, S. H. Zhang²
Authors’ Affiliations:
¹ Department of Physics, University of Coimbra, Coimbra, Portugal
² Department of Physics, Tsinghua University, Beijing, China
Abstract: Ammonia-hydrogen (NH3-H2) gas mixtures are heavily utilized across the metallurgical processing and microelectronics manufacturing sectors for nitride passivation, steel hardening, and high-purity semiconductor crystal deposition. This paper presents a self-consistent kinetic characterisation of electron transport swarms and evaluates molecular dissociation paths in low-pressure ammonia-hydrogen discharges. We calculated solution profiles for the electron Boltzmann equation using a multi-term spherical harmonic expansion engine across an expansive reduced electric field range (E/N) spanning 5.0 Td to 600.0 Td. The cross-section matrix items detailed elastic momentum shifts, rotational transitions, vibrational pumping, dissociative attachment, and direct electronic impact ionization events. The calculations reveal that adding small ammonia quantities (from 2.0% to 15.0% by volume) strongly skews the high-energy profile of the electron energy distribution function. At a marker of E/N = 50.0 Td, the total amidogen (NH2) radical generation rate coefficient scales up by an order of magnitude, driven by intense energy confinement near the primary vibrational impact boundaries. The simulated drift velocity constants match independent experiment recordings within a minor ±4.8% variation.
Keywords: Ammonia plasmas; Boltzmann equation; electron transport; dissociation kinetics; plasma processing; cross-section
Manuscript Timeline: Received: October 12, 2020; Revised: November 24, 2020; Accepted: December 15, 2020; Published: January 14, 2021
Citation: Santos, D. L., & Zhang, S. H. (2021). Kinetic Characterisation of Electron Transport Swarms and Dissociation Kinetics in Ammonia-Hydrogen Plasmas. International Journal of Physics, 12(1), 1–8.
International Journal of Physics | Vol. 11, No. 12, December 2020 | pp. 89–96
DOI: 10.46882/2020/IJP/000128
Research Article
Title: Topological Insulator States and Spin-Orbit Transport anomalies in Functionalized Antimonene Monolayers
Names of Authors: J. W. Park¹, E. C. Vance²
Authors’ Affiliations:
¹ Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
² Department of Physics, University of California, Berkeley, California, USA
Abstract: Developing novel two-dimensional atomic frameworks that house large electronic energy gaps is a focal research directive for realizing ambient-temperature spintronic devices and dissipationless circuitry networks. This study evaluates topological insulator states and maps spin-orbit transport anomalies inside functionalized antimonene (Sb) monolayers. We performed relativistic tight-binding electronic structure modeling across the hexagonal Brillouin zone, incorporating local chemical decoration patterns. The calculations show that strong intrinsic spin-orbit coupling cross-links the valence and conduction bands, lifting state degeneracies at the high-symmetry boundaries to establish a wide topological bulk bandgap of 0.28 eV. The system reports a non-zero spin Chern number of Cs = +1, confirming strong quantum spin Hall configurations. We simulated spin-polarized electron wavepacket transport properties past single-atom missing vacancies and edge boundary roughness. The helical edge modes bypassed these structural disruptions with an absolute transmission efficiency calculation of 99.5% ± 0.2%, showing an complete suppression of backscattering losses protected by time-reversal symmetry guidelines.
Keywords: Antimonene; topological insulators; spin-orbit coupling; quantum spin Hall effect; edge states; spintronics
Manuscript Timeline: Received: August 18, 2020; Revised: October 10, 2020; Accepted: November 02, 2020; Published: December 15, 2020
Citation: Park, J. W., & Vance, E. C. (2020). Topological Insulator States and Spin-Orbit Transport anomalies in Functionalized Antimonene Monolayers. International Journal of Physics, 11(12), 89–96.
International Journal of Physics | Vol. 11, No. 11, November 2020 | pp. 81–88
DOI: 10.46882/2020/IJP/000127
Research Article
Title: Elasticity Metrics and Structural Phase Transformations in Ultra-Incompressible Zirconium Tetraboride
Names of Authors: V. I. Morozov¹, O. B. Ivanov²
Authors’ Affiliations:
¹ Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk, Russia
² L.D. Landau Institute for Theoretical Physics, Russian Academy of Sciences, Chernogolovka, Russia
Abstract: Synthesis of ultra-incompressible structural compounds capable of retaining mechanical integrity under ultra-high shear loads is essential for manufacturing industrial abrasive bits and deep-mantle anvil components. This paper investigates high-pressure elasticity metrics and models structural phase transformations in orthorhombic zirconium tetraboride (ZrB4) up to hydrostatic limits of 150.0 GPa. We performed first-principles density functional theory computations incorporating generalized gradient approximations across compressed lattice geometries. At zero pressure, the calculated bulk modulus is B0 = 295.0 GPa, with an elastic pressure derivative coefficient of B0' = 4.12, matching experimental diamond cell records within a narrow 1.2% margin. The single-crystal elastic tensors (C11, C22, C33, C44, C55, and C66) climb monotonically under compression paths, strictly matching all Born mechanical stability conditions across the tested pressure window. Spatial compressibility profiles indicate that the crystal c-axis displays enhanced rigidity due to short, highly covalent boron-boron networks interlocking the metal rows. Electronic band-structure maps verify a persistent density of states at the Fermi boundary, proving that ZrB4 preserves metallic conductivity indicators under ultra-high pressures.
Keywords: Zirconium tetraboride; density functional theory; elastic constants; high pressure; mechanical stability; directional compressibility
Manuscript Timeline: Received: July 12, 2020; Revised: September 04, 2020; Accepted: September 22, 2020; Published: November 13, 2020
Citation: Morozov, V. I., & Ivanov, O. B. (2020). Elasticity Metrics and Structural Phase Transformations in Ultra-Incompressible Zirconium Tetraboride. International Journal of Physics, 11(11), 81–88.
International Journal of Physics | Vol. 11, No. 10, October 2020 | pp. 73–80
DOI: 10.46882/2020/IJP/000126
Research Article
Title: Optical Soliton Instabilities and Self-Focusing Control in Highly Non-Local Nematic Liquid Crystals
Names of Authors: L. K. Rousseau¹, K. Y. Tanaka²
Authors’ Affiliations:
¹ Laboratoire de Physique des Plasmas, École Polytechnique, Palaiseau, France
² Department of Materials Science, Tokyo Institute of Technology, Tokyo, Japan
Abstract: Managing high-power laser beam propagation profiles and eliminating catastrophic optical filamentation are vital for developing long-range optical links, light-induced waveguides, and compact signal-switching chips. This study models optical soliton instabilities and characterises self-focusing control fields inside nematic liquid crystal cells exhibiting highly non-local thermal reorientational non-linearities. We solved the coupled non-linear Schrödinger and director orientation equations using a variational mathematical approach paired with split-step Fourier numerical simulations. The analytical models establish the exact power thresholds and phase-matching metrics required to launch stable two-dimensional spatial solitary waves. The results prove that increasing the non-local elastic response length from 1.0 mm to 4.5 nm suppresses structural collapse nodes by smoothing localized wavefront phase errors. The modulation instability growth rate was tracked against changing spatial perturbation frequencies, highlighting a maximum gain coefficient of g = 3.18 cm^-1 under an input beam intensity of 2.5 kW/cm². Expanding the non-locality parameter scales down the maximum instability gain by 62.0% and shifts the peak response toward longer modulation wavelengths, effectively avoiding filamentation risks.
Keywords: Nonlinear optics; spatial solitons; nematic liquid crystals; modulation instability; wave collapse; split-step Fourier method
Manuscript Timeline: Received: June 02, 2020; Revised: July 29, 2020; Accepted: August 25, 2020; Published: October 08, 2020
Citation: Rousseau, L. K., & Tanaka, K. Y. (2020). Optical Soliton Instabilities and Self-Focusing Control in Highly Non-Local Nematic Liquid Crystals. International Journal of Physics, 11(10), 73–80.