International Journal of Physics | Vol. 9, No. 12, December 2018 | pp. 89–96
DOI: 10.46882/2018/IJP/000104
Research Article
Title: Elasticity Metrics and High-Pressure Structural Transitions in Ultra-Incompressible Hafnium Diboride
Names of Authors: V. I. Morozov¹, P. J. O’Connor²
Authors’ Affiliations: ¹Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk, Russia; ²Department 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 hafnium diboride (HfB²) 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 = 252.0 GPa, with an elastic pressure derivative value of B0' = 4.05, 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 hafnium-boron bonds. Electronic structure computations show a high density of states at the Fermi level, indicating that HfB² 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: Hafnium diboride; density functional theory; elastic constants; high pressure; structural stability; mechanical properties
Manuscript Timeline: Received: August 19, 2018; Revised: October 02, 2018; Accepted: October 28, 2018; Published: December 14, 2018
Citation: Morozov, V. I., & O’Connor, P. J. (2018). Elasticity Metrics and High-Pressure Structural Transitions in Ultra-Incompressible Hafnium Diboride. International Journal of Physics, 9(12), 89–96.
International Journal of Physics | Vol. 9, No. 11, November 2018 | pp. 81–88
DOI: 10.46882/2018/IJP/000103
Research Article
Title: Optical Soliton Profiles and Wave Interactions in Chiral Metamaterial Core Waveguides
Names of Authors: L. K. Rousseau¹, G. R. Davies²
Authors’ Affiliations: ¹Laboratoire de Physique des Plasmas, École Polytechnique, Palaiseau, France; ²School 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 quantum links. This study models optical soliton profiles and characterizes multi-wave interactions within chiral metamaterial core waveguides. We solved the coupled non-linear Schrödinger equations governing the left- and right-handed circularly polarized 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 solitary wave propagation. The results show that high chirality parameters generate a strong cross-steepening effect, mimicking a non-local Kerr nonlinearity that stabilizes localized two-dimensional structures. The modulation instability growth rate was calculated as a function of chirality, revealing a maximum gain value of g = 3.32 cm^-1 under an input pulse intensity of 2.5 kW/cm². Increasing the chirality parameter from 0.2 to 1.0 reduces the maximum instability gain by 58.0% and prevents pulse fragmentation. These findings provide strategies for controlling self-focusing in high-power laser systems and optimizing all-optical polarization switching networks.
Keywords: Nonlinear optics; optical solitons; chiral metamaterials; split-step Fourier method; modulation instability; wave propagation
Manuscript Timeline: Received: July 03, 2018; Revised: August 20, 2018; Accepted: September 12, 2018; Published: November 13, 2018
Citation: Rousseau, L. K., & Davies, G. R. (2018). Optical Soliton Profiles and Wave Interactions in Chiral Metamaterial Core Waveguides. International Journal of Physics, 9(11), 81–88.
International Journal of Physics | Vol. 9, No. 10, October 2018 | pp. 73–80
DOI: 10.46882/2018/IJP/000102
Research Article
Title: Quantum Entanglement Kinetics and Decoherence Protections in Coupled Four-Level Quantum Well Arrays
Names of Authors: S. H. Zhang¹, J. W. Park²
Authors’ Affiliations: ¹Department of Physics, Tsinghua University, Beijing, China; ²Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
Abstract: Preserving quantum correlations against environmental noise is a major bottleneck in developing scalable solid-state quantum memory computing architectures. This paper investigates the time-dependent evolution of quantum entanglement and evaluates active decoherence control strategies within coupled semiconductor four-level quantum well arrays. The system models a double-quantum-well structure coupled to an optical microcavity interacting with a localized acoustic 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 tunneling-induced transparency conditions effectively decouples the electronic state from the cavity decay channel. This decoupling preserves bipartite entanglement for durations exceeding 22.0 ns, maintaining a concurrence value above 0.86. We simulated an active dynamical decoupling pulse sequence that suppresses phase relaxation caused by low-frequency charge noise. The optimized sequence yielded a quantum gate operation fidelity of 99.4% ± 0.2%. These findings provide an effective theoretical framework for designing noise-resistant quantum memory registers and stabilizing non-classical states within solid-state circuits.
Keywords: Quantum entanglement; decoherence; quantum wells; Lindblad master equation; dynamical decoupling; tunneling-induced transparency
Manuscript Timeline: Received: June 02, 2018; Revised: July 29, 2018; Accepted: August 25, 2018; Published: October 10, 2018
Citation: Zhang, S. H., & Park, J. W. (2018). Quantum Entanglement Kinetics and Decoherence Protections in Coupled Four-Level Quantum Well Arrays. International Journal of Physics, 9(10), 73–80.
International Journal of Physics | Vol. 9, No. 9, September 2018 | pp. 65–72
DOI: 10.46882/2018/IJP/000101
Research Article
Title: Superconducting Phase Transitions and Flux Pinning Configurations in Niobium-Nitride Nanowire Networks
Names of Authors: O. K. Semenov¹, Y. S. Kim²
Authors’ Affiliations: ¹Institute for Solid State Physics, Russian Academy of Sciences, Moscow, Russia; ²Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
Abstract: Enhancing the current-carrying capability of superconducting arrays under strong magnetic fields is a critical requirement for single-photon detectors and quantum information circuits. This study evaluates the superconducting phase transitions and maps magnetic flux pinning configurations in niobium-nitride (NbN) interconnected nanowire networks. The networks were prepared via electro-beam lithography and reactive ion etching on sapphire substrates with wire widths ranging from 20.0 nm to 100.0 nm. We conducted low-temperature electrical transport and magnetometry measurements across a temperature range of 1.5 K to 15.0 K under magnetic fields up to 10.0 T. The pristine 100.0 nm network displayed a sharp superconducting transition with a critical temperature (Tc) of 15.2 K at zero field. Magnetization loops revealed a high critical current density (Jc) exceeding 4.2 x 10^6 A/cm² at 4.2 K. Analysis of the pinning force density indicates that the geometric network boundaries induce a strong vortex-matching effect, enhancing stability. The upper critical field, Hc2(0), was estimated to be 24.5 T by applying the Werthamer-Helfand-Hohenberg theoretical model. These findings demonstrate that nanoscale patterning significantly improves flux lattice stability, offering structural strategies for device engineering.
Keywords: Superconductivity; nanowires; flux pinning; critical current density; upper critical field; quantum circuits
Manuscript Timeline: Received: May 14, 2018; Revised: July 08, 2018; Accepted: August 03, 2018; Published: September 11, 2018
Citation: Semenov, O. K., & Kim, Y. S. (2018). Superconducting Phase Transitions and Flux Pinning Configurations in Niobium-Nitride Nanowire Networks. International Journal of Physics, 9(9), 65–72.
International Journal of Physics | Vol. 9, No. 8, August 2018 | pp. 57–64
DOI: 10.46882/2018/IJP/000100
Research Article
Title: Thermal Dispersion Metrics and Phonon Scattering at Silicon-Germanium Core-Shell Nanowire Boundaries
Names of Authors: M. G. Richter¹, D. W. Meyer²
Authors’ Affiliations: ¹Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany; ²Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany
Abstract: Minimizing thermal transport across semiconductor boundary layers is crucial for designing high-efficiency solid-state thermoelectric cooling devices and protecting microcircuit nodes. This paper uses molecular dynamics simulations to quantify thermal dispersion metrics and track phonon wavepacket scattering at defective silicon-germanium (Si-Ge) core-shell nanowire interfaces. We constructed atomistic models using the optimized Stillinger-Weber potential, incorporating varying concentrations of interfacial point defects and shell thickness distributions. 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 5.2 THz) undergo strong diffuse scattering at the rough shell interface, dropping the transmission coefficient from 0.84 down to 0.20. This diffuse scattering is driven by localized strain fields and localized interface vibrational modes. The overall interfacial thermal conductance was calculated to decrease by 50.0% when the interface 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 optoelectronic devices.
Keywords: Thermal dispersion; phonon wavepacket; molecular dynamics; core-shell nanowires; thermoelectric cooling; silicon-germanium
Manuscript Timeline: Received: April 05, 2018; Revised: June 01, 2018; Accepted: June 28, 2018; Published: August 14, 2018
Citation: Richter, M. G., & Meyer, D. W. (2018). Thermal Dispersion Metrics and Phonon Scattering at Silicon-Germanium Core-Shell Nanowire Boundaries. International Journal of Physics, 9(8), 57–64.
International Journal of Physics | Vol. 9, No. 7, July 2018 | pp. 49–56
DOI: 10.46882/2018/IJP/000099
Research Article
Title: Relativistic Hydrodynamic Modeling of Particle Generation Cascades in Asymmetric Proton-Xenon Collisions
Names of Authors: H. L. Mueller¹, S. C. O’Brien²
Authors’ Affiliations: ¹Institut für Kernphysik, Karlsruher Institut für Technologie, Karlsruhe, Germany; ²School of Physics, University College Dublin, Dublin, Ireland
Abstract: Asymmetric proton-xenon (p-Xe) 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-Xe collisions at a center-of-mass energy of 5.44 TeV 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 1.48 GeV/c in high-multiplicity events. The calculated elliptic flow coefficient (v²) displays a strong mass-ordering effect, which matches experimental measurements gathered by modern forward spectrometers within a tight ±6.0% margin. This close agreement suggests that small-scale heavy-ion systems generated in p-Xe 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-xenon collisions; elliptic flow; color-fluctuation model; statistical hadronization
Manuscript Timeline: Received: March 11, 2018; Revised: May 19, 2018; Accepted: June 11, 2018; Published: July 12, 2018
Citation: Mueller, H. L., & O’Brien, S. C. (2018). Relativistic Hydrodynamic Modeling of Particle Generation Cascades in Asymmetric Proton-Xenon Collisions. International Journal of Physics, 9(7), 49–56.