International Journal of Physics | Vol. 7, No. 12, December 2016 | pp. 89–96
DOI: 10.46882/2016/IJP/000080
Research Article
Title: Optical Soliton Dynamics and Multi-Wave Interaction Patterns in Photorefractive Polymer Waveguides
Names of Authors: L. K. Rousseau¹, K. Y. Tanaka²
Authors’ Affiliations: ¹Laboratoire de Physique des Plasmas, École Polytechnique, Palaiseau, France; ²Department of Materials Science, Tokyo Institute of Technology, Tokyo, Japan
Abstract: Controlling ultra-short light pulses within integrated optical chips is essential for expanding the bandwidth of modern telecommunication networks. This study models optical soliton dynamics and characterizes 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: August 19, 2016; Revised: October 02, 2016; Accepted: October 28, 2016; Published: December 12, 2016
Citation: Rousseau, L. K., & Tanaka, K. Y. (2016). Optical Soliton Dynamics and Multi-Wave Interaction Patterns in Photorefractive Polymer Waveguides. International Journal of Physics, 7(12), 89–96.
International Journal of Physics | Vol. 7, No. 11, November 2016 | pp. 81–88
DOI: 10.46882/2016/IJP/000079
Research Article
Title: Quantum Entanglement Dynamics and Decoherence Controls in Driven Lambda-Type Atomic Systems
Names of Authors: S. H. Zhang¹, M. S. Al-Rashid²
Authors’ Affiliations: ¹Department of Physics, Tsinghua University, Beijing, China; ²Department of Physics, King Abdulaziz University, Jeddah, Saudi Arabia
Abstract: Preserving quantum correlations against environmental noise is a major bottleneck in developing scalable quantum information processing architectures. This paper investigates the time-dependent evolution of quantum entanglement and evaluates active decoherence control strategies within driven lambda-type three-level atomic systems. The system models a lambda-type atom coupled to a lossy optical microcavity interacting with a localized thermal phonon bath. We utilized the density matrix master equation framework within the Lindblad dissipation model at an operating temperature of 4.2 K. Our numerical calculations show that configuring the driving laser fields under electromagnetically induced transparency conditions effectively decouples the atomic state from the cavity decay channel. This decoupling preserves bipartite entanglement for durations exceeding 18.0 ns, maintaining a concurrence value above 0.84. We simulated an active dynamical decoupling pulse sequence that suppresses phase relaxation caused by low-frequency phonon noise. The optimized sequence yielded a quantum gate operation fidelity of 99.3% ± 0.2%. These findings provide an effective theoretical framework for designing noise-resistant quantum memory registers and stabilizing non-classical states within complex quantum networks.
Keywords: Quantum entanglement; decoherence; three-level atom; Lindblad master equation; dynamical decoupling; electromagnetically induced transparency
Manuscript Timeline: Received: July 03, 2016; Revised: August 20, 2016; Accepted: September 12, 2016; Published: November 14, 2016
Citation: Zhang, S. H., & Al-Rashid, M. S. (2016). Quantum Entanglement Dynamics and Decoherence Controls in Driven Lambda-Type Atomic Systems. International Journal of Physics, 7(11), 81–88.
International Journal of Physics | Vol. 7, No. 10, October 2016 | pp. 73–80
DOI: 10.46882/2016/IJP/000078
Research Article
Title: Superconducting Phase Transitions and Magnetic Flux Pinning Mechanisms in Vanadium-Nitride Thin Films
Names of Authors: O. K. Semenov¹, D. L. Santos²
Authors’ Affiliations: ¹Institute for Solid State Physics, Russian Academy of Sciences, Moscow, Russia; ²Department of Physics, University of Coimbra, Coimbra, Portugal
Abstract: Enhancing the current-carrying capability of superconductors under strong magnetic fields is a critical requirement for next-generation particle accelerators and magnetic resonance imaging systems. This study evaluates the superconducting phase transitions and maps magnetic flux pinning mechanisms in vanadium-nitride (VN) thin films. The thin films were prepared via magnetron 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 2.0 K to 15.0 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 8.6 K at zero field. Magnetization loops revealed a high critical current density (Jc) exceeding 2.8 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 10.5 T by applying the Werthamer-Helfand-Hohenberg theoretical model. These findings demonstrate that nanoscale grain boundary control significantly improves vortex lattice stability, offering structural strategies for high-field superconducting applications.
Keywords: Superconductivity; thin films; flux pinning; critical current density; upper critical field; magnetron sputtering
Manuscript Timeline: Received: June 02, 2016; Revised: July 29, 2016; Accepted: August 25, 2016; Published: October 08, 2016
Citation: Semenov, O. K., & Santos, D. L. (2016). Superconducting Phase Transitions and Magnetic Flux Pinning Mechanisms in Vanadium-Nitride Thin Films. International Journal of Physics, 7(10), 73–80.
International Journal of Physics | Vol. 7, No. 9, September 2016 | pp. 65–72
DOI: 10.46882/2016/IJP/000077
Research Article
Title: Thermal Dispersion Metrics and Phonon Wavepacket Scattering at Silicon-Silicide Interfacial Defect Boundaries
Names of Authors: M. G. Richter¹, S. P. Nair²
Authors’ Affiliations: ¹Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany; ²Department of Physics, University of Kerala, Trivandrum, India
Abstract: Minimizing thermal transport across semiconductor boundary layers is crucial for designing high-efficiency solid-state thermoelectric cooling devices. This paper uses molecular dynamics simulations to quantify thermal dispersion metrics and track phonon wavepacket scattering at defective silicon-silicide (Si-MSi2) interfaces. We constructed atomistic models using the optimized Stillinger-Weber potential, incorporating varying concentrations of interfacial point defects and atomic roughness steps. Longitudinal and transverse acoustic phonon wavepackets were generated with narrow frequency spreads centered between 2.0 THz and 8.0 THz. The computational data demonstrate that high-frequency acoustic phonons (f greater than 5.0 THz) undergo strong diffuse scattering at the rough interface, dropping the transmission coefficient from 0.85 down to 0.22. This diffuse scattering is driven by localized strain fields and localized interface vibrational modes. The overall interfacial thermal conductance was calculated to decrease by 48.0% when the interfacial roughness parameter scaled from 0.1 nm to 0.6 nm at 300.0 K. These molecular dynamics calculations clarify the atomic-scale mechanisms restricting heat carrier propagation, helping engineers design targeted thermal barriers for nanoscale electronics.
Keywords: Thermal dispersion; phonon wavepacket; molecular dynamics; interface roughness; thermoelectric cooling; silicide interfaces
Manuscript Timeline: Received: May 14, 2016; Revised: July 08, 2016; Accepted: August 03, 2016; Published: September 10, 2016
Citation: Richter, M. G., & Nair, S. P. (2016). Thermal Dispersion Metrics and Phonon Wavepacket Scattering at Silicon-Silicide Interfacial Defect Boundaries. International Journal of Physics, 7(9), 65–72.
International Journal of Physics | Vol. 7, No. 8, August 2016 | pp. 57–64
DOI: 10.46882/2016/IJP/000076
Research Article
Title: Relativistic Hydrodynamic Modeling of Particle Production Cascades in Asymmetric Proton-Gold Collisions
Names of Authors: H. L. Mueller¹, A. M. El-Sayed²
Authors’ Affiliations: ¹Institut für Kernphysik, Karlsruher Institut für Technologie, Karlsruhe, Germany; ²Department of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt
Abstract: Asymmetric proton-gold (p-Au) collisions provide a crucial baseline for isolating cold nuclear matter effects from the collective signature of the quark-gluon plasma. This study presents a relativistic hydrodynamic modeling framework to simulate particle production cascades in p-Au collisions at a center-of-mass energy of 200.0 GeV per nucleon pair. We utilized a 3+1 dimensional viscous hydrodynamic code coupled with a statistical hadronization module to compute transverse momentum spectra and azimuthal anisotropy coefficients. The initial energy density profiles were generated using a Glauber-Gribov color-fluctuation model to capture sub-nucleon scale configurations. The numerical simulations show that expanding systems build a substantial radial flow profile, which shifts the mean transverse momentum of protons up to 1.35 GeV/c in high-multiplicity events. The calculated elliptic flow coefficient (v²) displays a strong mass-ordering effect, which matches experimental measurements gathered by RHIC detectors within a tight ±6.0% margin. This close agreement suggests that small-scale systems generated in p-Au collisions can achieve brief hydrodynamic collective expansion. These findings help clarify the boundaries of fluid-like behavior in high-energy subatomic particle interactions.
Keywords: Relativistic hydrodynamics; particle production; proton-gold collisions; elliptic flow; color-fluctuation model; statistical hadronization
Manuscript Timeline: Received: April 05, 2016; Revised: June 01, 2016; Accepted: June 28, 2016; Published: August 14, 2016
Citation: Mueller, H. L., & El-Sayed, A. M. (2016). Relativistic Hydrodynamic Modeling of Particle Production Cascades in Asymmetric Proton-Gold Collisions. International Journal of Physics, 7(8), 57–64.
International Journal of Physics | Vol. 7, No. 7, July 2016 | pp. 49–56
DOI: 10.46882/2016/IJP/000075
Research Article
Title: Kinetic Simulation of Electron Transport and Excitation Rates in Low-Pressure Helium-Argon Discharges
Names of Authors: A. M. El-Chemali¹, J. L. Manceau²
Authors’ Affiliations: ¹Department of Physics, Faculty of Science, Lebanese University, Beirut, Lebanon; ²Laboratoire Kastler Brossel, Sorbonne Université, CNRS, Paris, France
Abstract: Noble gas mixtures are widely utilized in plasma processing reactors, gas lasers, and radiation detection instrumentation. This study develops a self-consistent kinetic simulation model to analyze electron transport properties and compute excitation rates in low-pressure helium-argon (He-Ar) gas mixtures. We solved the electron Boltzmann equation using a multi-term spherical harmonic expansion scheme across a reduced electric field range (E/N) from 2.0 Td to 500.0 Td. The model incorporates comprehensive cross-section sets, including elastic scattering, electronic excitation, and direct impact ionization, while accounting for Penning ionization processes. Our modeling results show that adding small fractions of argon (from 1.0% to 5.0% by volume) drastically distorts the electron energy distribution function. At a field strength of E/N = 25.0 Td, the total ionization rate coefficient increases by over two orders of magnitude in the 95% He - 5% Ar mixture compared to pure helium. This enhancement is driven by Penning collisions between metastable helium atoms and ground-state argon atoms. The calculated electron drift velocities and longitudinal diffusion coefficients match independent swarm experimental measurements within a ±4.5% variance. These kinetic parameters provide essential baseline input data for optimizing industrial plasma processing chambers.
Keywords: Helium-argon mixtures; Boltzmann equation; electron transport; Penning ionization; cross-section; plasma modeling
Manuscript Timeline: Received: March 11, 2016; Revised: May 19, 2016; Accepted: June 11, 2016; Published: July 09, 2016
Citation: El-Chemali, A. M., & Manceau, J. L. (2016). Kinetic Simulation of Electron Transport and Excitation Rates in Low-Pressure Helium-Argon Discharges. International Journal of Physics, 7(7), 49–56.