International Journal of Physics | Vol. 13, No. 12, December 2022 | pp. 89–96
DOI: 10.46882/2022/IJP/000152
Research Article
Title: Kinetic Modelling of Electron Swarm Parameters and Fragmentation Pathways in Ethane-Oxygen Discharges
Names of Authors: D. L. Santos¹, T. H. Nguyen²
Authors’ Affiliations:
¹ Department of Physics, University of Coimbra, Coimbra, Portugal
² Department of Physics, Vietnam National University, Hanoi, Vietnam
Abstract: Ethane-oxygen (C₂H₆-O2) gas discharges are widely deployed in material processing and chemical engineering sectors for diamond-like carbon thin-film synthesis, surface activation, and greenhouse gas conversion. This paper develops a self-consistent kinetic model to evaluate electron swarm parameters and calculate molecular fragmentation pathways in low-pressure ethane-oxygen mixtures. We solved the electron Boltzmann equation using a multi-term spherical harmonic expansion framework across a wide reduced electric field range (E/N) from 10.0 Td to 500.0 Td. The cross-section dataset accounted for elastic momentum transfer, rotational transitions, vibrational excitation states, dissociative attachment, and direct impact ionization processes. Our modeling results show that adding small fractions of oxygen (from 5.0% to 20.0% by volume) significantly distorts the high-energy tail of the electron distribution function. At E/N = 80.0 Td, the total ethyl radical (C₂H₅) production rate coefficient increases by over an order of magnitude due to efficient energy channeling into the primary vibrational thresholds of ethane. The calculated electron drift velocities match independent swarm experimental measurements within a ±5.0% variance index. These kinetic parameters provide critical baseline inputs for optimizing commercial chemical vapor deposition reactors.
Keywords: Ethane plasmas; Boltzmann equation; electron transport; fragmentation pathways; chemical vapor deposition; cross-section
Manuscript Timeline: Received: September 15, 2022; Revised: October 30, 2022; Accepted: November 15, 2022; Published: December 16, 2022
Citation: Santos, D. L., & Nguyen, T. H. (2022). Kinetic Modelling of Electron Swarm Parameters and Fragmentation Pathways in Ethane-Oxygen Discharges. International Journal of Physics, 13(12), 89–96.
International Journal of Physics | Vol. 13, No. 11, November 2022 | pp. 81–88
DOI: 10.46882/2022/IJP/000151
Research Article
Title: Topological Valley States and Spin-Polarized Edge Transport in Chlorinated Tin Film Honeycomb Lattices
Names of Authors: J. W. Park¹, A. L. Silva²
Authors’ Affiliations:
¹ Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
² Institute of Physics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
Abstract: Valleytronics provides an alternative pathway for low-power electronic hardware architectures by leveraging the valley degree of freedom to lock charge transport. This study models topological valley states and characterises spin-polarized edge transport in two-dimensional honeycombed lattices of chlorinated tin (stanene) films. We executed electronic band calculations using the relativistic tight-binding method across the hexagonal Brillouin zone. The combination of structural inversion asymmetry and strong intrinsic spin-orbit coupling breaks the valley degeneracy, opening a wide topological bulk bandgap of 0.22 eV. The system exhibits a non-zero valley Chern number of Cv = +1, which confirms non-trivial topological valley properties. To evaluate transport robustness, we simulated electron wavepacket propagation past point vacancies and sharp 60-degree boundary folds. The valley-polarized edge mode bypassed these structural obstacles with a high transmission efficiency of 99.4% ± 0.2%, demonstrating an absence of backscattering due to valley-contrast conservation rules. These findings provide solid engineering guidelines for building backscattering-immune valley-filter switches, quantum pathways, and integrated low-dissipation logic networks.
Keywords: Valleytronics; topological insulators; spin-orbit coupling; tight-binding method; edge states; stanene films
Manuscript Timeline: Received: August 18, 2022; Revised: October 10, 2022; Accepted: November 02, 2022; Published: November 15, 2022
Citation: Park, J. W., & Silva, A. L. (2022). Topological Valley States and Spin-Polarized Edge Transport in Chlorinated Tin Film Honeycomb Lattices. International Journal of Physics, 13(11), 81–88.
International Journal of Physics | Vol. 13, No. 10, October 2022 | pp. 73–80
DOI: 10.46882/2022/IJP/000150
Research Article
Title: Elasticity Metrics and High-Pressure Structural Transitions in Ultra-Incompressible Niobium Diboride
Names of Authors: V. I. Morozov¹, P. J. O’Connor²
Authors’ Affiliations:
¹ Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk, Russia
² Department of Civil and Environmental Engineering, University College Cork, Cork, Ireland
Abstract: Developing ultra-incompressible structural materials capable of operating under extreme mechanical stress is vital for specialized aerospace engineering and deep-earth simulation components. This paper investigates high-pressure elasticity metrics and monitors structural phase transitions in hexagonal niobium diboride (NbB₂) up to hydrostatic pressures of 160.0 GPa. We performed first-principles density functional theory computations within the generalized gradient approximation framework. At zero pressure, the calculated bulk modulus is B0 = 245.0 GPa, with an elastic pressure derivative value of B0' = 4.08, matching experimental diamond anvil cell measurements within a 1.2% margin. The single-crystal elastic constants (C11, C33, C44, C12, and C13) increase monotonically under uniform compression, satisfying all Born mechanical stability parameters across the entire pressure range. The directional compressibility paths reveal that the crystal c-axis displays exceptional stiffness due to short, covalent niobium-boron bonds. Electronic structure computations show a high density of states at the Fermi level, indicating that NbB₂ maintains its metallic profile under ultra-high pressures. These precise elastic records confirm the viability of transition metal borides as robust alternatives to conventional superhard ceramics.
Keywords: Niobium diboride; density functional theory; elastic constants; high pressure; structural stability; mechanical properties
Manuscript Timeline: Received: July 12, 2022; Revised: September 04, 2022; Accepted: September 22, 2022; Published: October 14, 2022
Citation: Morozov, V. I., & O’Connor, P. J. (2022). Elasticity Metrics and High-Pressure Structural Transitions in Ultra-Incompressible Niobium Diboride. International Journal of Physics, 13(10), 73–80.
International Journal of Physics | Vol. 13, No. 9, September 2022 | pp. 65–72
DOI: 10.46882/2022/IJP/000149
Research Article
Title: Optical Soliton Dynamics and Multi-Wave Interaction Patterns in Non-Local Polymeric Waveguides
Names of Authors: L. K. Rousseau¹, G. R. Davies²
Authors’ Affiliations:
¹ Laboratoire de Physique des Plasmas, École Polytechnique, Palaiseau, France
² School of Physics and Astronomy, University of St Andrews, St Andrews, UK
Abstract: Controlling ultra-short light pulses within integrated optical chips is essential for expanding the bandwidth of modern telecommunication networks and building robust optical processors. This study models optical soliton dynamics and characterises multi-wave interaction patterns within photorefractive polymer waveguides. We solved the coupled non-linear Schrödinger equations governing the fundamental and second-harmonic fields using a variational method paired with split-step Fourier numerical simulations. The analytical framework derives the exact phase-matching conditions and power thresholds required to initiate stable multicolored solitary wave propagation. The results show that large phase mismatches generate a strong cascading effect, mimicking a cubic Kerr nonlinearity that stabilizes localized two-dimensional structures. The modulation instability growth rate was calculated as a function of mismatch parameters, revealing a maximum gain value of g = 3.24 cm⁻¹ under an input pulse intensity of 2.2 kW/cm². Increasing the mismatch parameter from 1.0 mm⁻¹ to 5.0 mm⁻¹ reduces the maximum instability gain by 56.0% and prevents pulse fragmentation. These findings provide strategies for controlling self-focusing in high-power laser systems and optimizing all-optical switching matrices.
Keywords: Nonlinear optics; optical solitons; quadratic nonlinearity; split-step Fourier method; modulation instability; phase matching
Manuscript Timeline: Received: June 04, 2022; Revised: July 28, 2022; Accepted: August 18, 2022; Published: September 10, 2022
Citation: Rousseau, L. K., & Davies, G. R. (2022). Optical Soliton Dynamics and Multi-Wave Interaction Patterns in Non-Local Polymeric Waveguides. International Journal of Physics, 13(9), 65–72.
International Journal of Physics | Vol. 13, No. 8, August 2022 | pp. 57–64
DOI: 10.46882/2022/IJP/000148
Research Article
Title: Quantum Entanglement Kinetics and Decoherence Controls in Driven Asymmetric Quantum Dot Chains
Names of Authors: S. H. Zhang¹, J. W. Park²
Authors’ Affiliations:
¹ Department of Physics, Tsinghua University, Beijing, China
² Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
Abstract: Protecting non-classical quantum state correlations from localized environmental fluctuations is a major roadblock to scaling high-fidelity solid-state quantum computation networks. This paper investigates the time-dependent kinetic evolution of quantum entanglement and presents active decoherence control strategies within driven asymmetric quantum dot chains. The model comprises a multi-level semiconductor double-quantum-dot array embedded in an optical microcavity and interacting with a discrete thermal acoustic phonon bath. We solved the density matrix master equations using an algebraic operator framework matching the Lindblad dissipation rules at a cryogenic operating temperature of 4.2 K. The calculations demonstrate that modulating the external laser fields to satisfy multi-photon resonance profiles effectively shelters the electronic states from radiative cavity mirror leaks. This isolation sustains stable bipartite entanglement across continuous runtime blocks exceeding 22.0 ns, preserving a concurrence index above 0.84. We simulated a periodic dynamical phase-reversal pulse sequence that dampens low-frequency charge noise channels. This optimization yields a target quantum phase gate fidelity calculation of 99.3% ± 0.2%. These structural and kinetic parameters assist engineers in configuring stable, noise-immune registers.
Keywords: Quantum entanglement; quantum dots; Lindblad master equation; dynamical decoupling; cavity electrodynamics; quantum computing
Manuscript Timeline: Received: May 12, 2022; Revised: July 03, 2022; Accepted: July 25, 2022; Published: August 16, 2022
Citation: Zhang, S. H., & Park, J. W. (2022). Quantum Entanglement Kinetics and Decoherence Controls in Driven Asymmetric Quantum Dot Chains. International Journal of Physics, 13(8), 57–64.
International Journal of Physics | Vol. 13, No. 7, July 2022 | pp. 49–56
DOI: 10.46882/2022/IJP/000147
Research Article
Title: Superconducting Phase Transitions and Flux Pinning Configurations in Niobium-Zirconium Thin Films
Names of Authors: O. K. Semenov¹, Y. S. Kim²
Authors’ Affiliations:
¹ Institute for Solid State Physics, Russian Academy of Sciences, Moscow, Russia
² Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
Abstract: Enhancing the critical current density of superconducting alloys under strong magnetic fields is a crucial requirement for next-generation quantum computing circuits, single-photon detectors, and fusion magnet components. This study evaluates the superconducting phase transitions and maps magnetic flux pinning configurations in niobium-zirconium (Nb-Zr) thin films. The thin films were prepared via co-sputtering on sapphire substrates with film thicknesses ranging from 50.0 nm to 300.0 nm. We conducted low-temperature electrical transport and magnetometry measurements across a temperature range of 1.5 K to 12.0 K under magnetic fields up to 8.0 T. The pristine 300.0 nm film displayed a sharp superconducting transition with a critical temperature (Tc) of 10.8 K at zero field. Magnetization loops revealed a high critical current density (Jc) exceeding 3.8 x 10^6 A/cm² at 4.2 K. Analysis of the pinning force density indicates that the dominant pinning mechanism shifts from core-surface pinning to point-defect pinning as the temperature approaches Tc. The upper critical field, Hc2(0), was estimated to be 12.4 T by applying the Werthamer-Helfand-Hohenberg theoretical model. These findings demonstrate that nanoscale structural control significantly improves vortex lattice stability under magnetic stress.
Keywords: Superconductivity; thin films; flux pinning; critical current density; upper critical field; magnetron sputtering
Manuscript Timeline: Received: April 05, 2022; Revised: June 01, 2022; Accepted: June 28, 2022; Published: July 15, 2022
Citation: Semenov, O. K., & Kim, Y. S. (2022). Superconducting Phase Transitions and Flux Pinning Configurations in Niobium-Zirconium Thin Films. International Journal of Physics, 13(7), 49–56.