International Journal of Physics | Vol. 16, No. 6, June 2025 | pp. 41–48
DOI: 10.46882/2025/IJP/000182
Research Article
Title: Superconducting Gap Structures and Interband Fluctuations in Electron-Doped Pnictide Sr0.85La0.15Fe2As2 Single Crystals
Names of Authors: I. R. Sokolov¹, V. I. Morozov²
Authors’ Affiliations:
¹ Kapitza Institute for Physical Problems, Russian Academy of Sciences, Moscow, Russia
² Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk, Russia
Abstract: Establishing the exact pairing symmetries of iron-based pnictide superconductors remains a primary objective within modern solid-state and condensed matter physics pipelines. We synthesized high-quality single crystals of electron-doped Sr0.85La0.15Fe2As2 using a specialized self-flux crystal growth routine under high-pressure configurations. The internal superconducting gap structures and spin fluctuations were evaluated using high-resolution angle-resolved photoemission spectroscopy and low-temperature London penetration depth tracking. The single crystals displayed a sharp superconducting transition at Tc = 26.0 K with an exceptionally narrow magnetic susceptibility transition width of ΔT = 0.3 K. The temperature dependence of the London penetration depth exhibits an exponential profile at low operational targets (T less than 0.3 Tc), ruling out the existence of line nodes across the order parameter. The photoemission mapping revealed two distinct, fully gapped isotropic superconducting bands across the Fermi surface. The large gap magnitude was measured at Δ1 = 7.1 meV on the inner hole-like sheet, while the lower gap registered at Δ2 = 3.5 meV on the outer electron-like sheets. This structure yields a strong-coupling index of 2Δ1/kBTc = 6.3, verifying strong-coupling pairing driven by interband spin fluctuations.
Keywords: Iron-based superconductors; gap structures; photoemission spectroscopy; London penetration depth; pairing symmetry; spin fluctuations
Manuscript Timeline: Received: March 02, 2025; Revised: April 14, 2025; Accepted: May 02, 2025; Published: June 18, 2025
Citation: Sokolov, I. R., & Morozov, V. I. (2025). Superconducting Gap Structures and Interband Fluctuations in Electron-Doped Pnictide Sr0.85La0.15Fe2As2 Single Crystals. International Journal of Physics, 16(6), 41–48.
International Journal of Physics | Vol. 16, No. 5, May 2025 | pp. 33–40
DOI: 10.46882/2025/IJP/000181
Research Article
Title: Squeezed Vacuum State Propagation and Mode Confinement in Disordered Optomechanical Photonic Cavities
Names of Authors: A. M. Ross¹, L. K. Rousseau²
Authors’ Affiliations:
¹ Department of Physics, University of Queensland, Brisbane, QLD 4072, Australia
² Laboratoire de Physique des Plasmas, École Polytechnique, Palaiseau, France
Abstract: Processing non-classical states of light within integrated optomechanical circuits is essential for scalable quantum communication networks and high-fidelity quantum transduction. This study models continuous-wave squeezed vacuum state propagation and characterises photon correlation metrics within a linear array of coupled microcavities subjected to spatial fabrication disorder. We solved the quantum stochastic Heisenberg-Langevin equations using an algebraic operator framework that accounts for localized optomechanical coupling variations, cavity mirror losses, and thermal phonon dephasing paths at 4.2 K. Squeezed vacuum states at 1550.0 nm were injected into the boundary port of a 15-channel network. The calculations demonstrate that introducing a minor 4.0% structural disorder in cavity resonance frequencies induces strong spatial localization of light, dropping the input squeezing level from 8.0 dB down to 2.4 dB over a 12.0 ps interaction window. To protect the quantum states, we simulated an active phase-modulation feedback loop that establishes a synthetic gauge field to suppress backscattering. The optimized circuit configuration restored the squeezing level to 6.8 dB, yielding a state fidelity calculation of 94.8% ± 0.3%.
Keywords: Quantum optics; squeezed states; optomechanics; Anderson localization; integrated photonics; phase stabilization
Manuscript Timeline: Received: February 11, 2025; Revised: March 24, 2025; Accepted: April 10, 2025; Published: May 15, 2025
Citation: Ross, A. M., & Rousseau, L. K. (2025). Squeezed Vacuum State Propagation and Mode Confinement in Disordered Optomechanical Photonic Cavities. International Journal of Physics, 16(5), 33–40.
International Journal of Physics | Vol. 16, No. 4, April 2025 | pp. 25–32
DOI: 10.46882/2025/IJP/000180
Research Article
Title: Finite Element Modeling of Acoustic Wave Scattering and Trajectory Controls in Active Piezocomposite Metamaterials
Names of Authors: P. J. O’Connor¹, S. H. Zhang²
Authors’ Affiliations:
¹ Department of Civil and Environmental Engineering, University College Cork, Cork, Ireland
² Department of Physics, Tsinghua University, Beijing, China
Abstract: Controlling acoustic paths in structural and underwater environments is essential for adaptive noise insulation, structural wave management components, and specialized sub-aquatic tracking arrays. This study presents a finite element modeling framework to simulate acoustic wave scattering and track wave redirection profiles within active piezocomposite acoustic metamaterials. The design leverages a coordinate-transformation method applied to Biot's dynamic poroelastic equations to determine the required anisotropic distribution of density and elastic moduli tensors across the shell. We performed numerical scattering simulations across an ultrasonic frequency band from 20.0 kHz to 100.0 kHz. The computational models show that a cylindrical cloak constructed with 32 concentric sub-wavelength layers successfully routes an incident acoustic wave around a central cavity. This active configuration reduces the total scattering cross-section by 84.0% at a design frequency of 50.0 kHz. We analyzed the impact of electrical boundary configurations, demonstrating that adaptive inductive shunt routing modifies the effective bulk modulus tensor to accommodate shifts in fluid pressures. Experimental validation was carried out using 3D-printed perforated piezoceramic rings immersed in water, matching simulated fields within a tight ±4.8% error margin.
Keywords: Acoustic metamaterials; finite element modeling; wave redirection; Biot's theory; piezocomposites; active shunts
Manuscript Timeline: Received: January 08, 2025; Revised: February 18, 2025; Accepted: March 05, 2025; Published: April 11, 2025
Citation: O’Connor, P. J., & Zhang, S. H. (2025). Finite Element Modeling of Acoustic Wave Scattering and Trajectory Controls in Active Piezocomposite Metamaterials. International Journal of Physics, 16(4), 25–32.
International Journal of Physics | Vol. 16, No. 3, March 2025 | pp. 17–24
DOI: 10.46882/2025/IJP/000179
Research Article
Title: Fluid Inflow Velocity Mapping and Reconnection Flux Mechanics in Solar Prominence Eruptions
Names of Authors: G. R. Davies¹, O. K. Semenov²
Authors’ Affiliations:
¹ School of Physics and Astronomy, University of St Andrews, St Andrews, UK
² Institute for Solid State Physics, Russian Academy of Sciences, Moscow, Russia
Abstract: High-temperature magnetic reconnection stands as the primary physical driver behind explosive energy release events in the solar atmosphere, heating material to millions of Kelvin and propelling solar prominence eruptions. This paper evaluates fluid velocity mapping and quantifies local magnetic reconnection rates within an eruptive active loop region using high-resolution data from satellite extreme ultraviolet spectroscopic imagers. We tracked the Doppler shifts and intensity profiles of the O IV and Fe XXI spectral emission lines to isolate reconnection pathways under dense plasma constraints. The empirical measurements reveal systematic plasma inflows moving at 16.4 km/s, while directed outflows reach velocities of 295.0 km/s along the magnetic open field corridors. Based on these transport metrics, the local dimensionless reconnection rate was calculated to range between 0.05 and 0.08. These values closely match fast reconnection regimes predicted by the Petschek theoretical framework modified by hall magnetohydrodynamic effects and plasmoid instabilities. Spectroscopic line-broadening analysis indicates localized turbulent temperatures peaking at 10.2 MK within the diffusion region, confirming intense localized viscous dissipation. These diagnostics provide direct observational parameters for refining coronal magnetohydrodynamics.
Keywords: Solar atmosphere; magnetic reconnection; prominence eruption; ultraviolet spectroscopy; plasma velocity; magnetohydrodynamics
Manuscript Timeline: Received: December 14, 2024; Revised: January 22, 2025; Accepted: February 09, 2025; Published: March 12, 2025
Citation: Davies, G. R., & Semenov, O. K. (2025). Fluid Inflow Velocity Mapping and Reconnection Flux Mechanics in Solar Prominence Eruptions. International Journal of Physics, 16(3), 17–24.
International Journal of Physics | Vol. 16, No. 2, February 2025 | pp. 9–16
DOI: 10.46882/2025/IJP/000178
Research Article
Title: Quantum Efficiency Optimization of Antimonene Solar Cells via Continuous Bandgap Grading Profiles
Names of Authors: H. K. Tanaka¹, M. G. Richter²
Authors’ Affiliations:
¹ Department of Quantum Engineering, Nagoya University, Nagoya, Japan
² Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
Abstract: Developing group-V elemental two-dimensional monolayers provides an exceptional architectural framework for improving the conversion efficiency of thin-film photovoltaics. This paper presents a detailed numerical model to optimize the internal quantum efficiency of chemically functionalized antimonene solar cells using a continuous bandgap grading profile. We systematically evaluated the impacts of carrier recombination lifetimes and interface defect traps on device performance parameters under standard one-sun illumination matrices (AM 1.5G, 100.0 mW/cm²). Our numerical calculations reveal that grading the surface chemical functionalization creates a linear bandgap tilt (varying from 1.20 eV to 1.65 eV) that generates a built-in electric field. This built-in field accelerates charge separation tracks and significantly drops radiative recombination rates. When standard recombination lifetimes of 18.0 ns are introduced, the optimized graded device yields a short-circuit current density of 27.4 mA/cm² and an open-circuit voltage of 0.92 V. This results in a maximum power conversion efficiency of 19.4%, representing a significant improvement over the uniform bandgap control cell. We also analyzed the thermal stability of the device between 280.0 K and 360.0 K, demonstrating that the graded structure reduces thermal efficiency degradation by 25.0%.
Keywords: Antimonene solar cells; graded bandgap; quantum efficiency; charge transport; numerical modeling; photovoltaics
Manuscript Timeline: Received: November 05, 2024; Revised: December 18, 2024; Accepted: January 08, 2025; Published: February 12, 2025
Citation: Tanaka, H. K., & Richter, M. G. (2025). Quantum Efficiency Optimization of Antimonene Solar Cells via Continuous Bandgap Grading Profiles. International Journal of Physics, 16(2), 9–16.
International Journal of Physics | Vol. 16, No. 1, January 2025 | pp. 1–8
DOI: 10.46882/2025/IJP/000177
Research Article
Title: Thermal Dispersion Parameters and Phonon Scattering Dynamics across Silicon-Gallium Nitride Heterojunctions
Names of Authors: D. W. Meyer¹, H. L. Mueller²
Authors’ Affiliations:
¹ Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany
² Institut für Kernphysik, Karlsruher Institut für Technologie, Karlsruhe, Germany
Abstract: Effectively dissipating high thermal fluxes across heavily mismatched semiconductor boundary layers is a vital milestone for developing next-generation wide-bandgap radio-frequency electronics and compact power conversion switches. This paper utilizes molecular dynamics simulations to quantify thermal dispersion parameters and track acoustic phonon wavepacket scattering at mismatched silicon-gallium nitride (Si-GaN) heterojunctions. We constructed atomistic models using the optimized Tersoff empirical potentials, incorporating varying concentrations of interfacial dislocation networks and localized point vacancy defects. Longitudinal and transverse acoustic phonon wavepackets were generated with narrow frequency spreads centered between 3.0 THz and 12.0 THz. The computational data demonstrate that high-frequency acoustic phonons (f greater than 6.5 THz) undergo strong diffuse scattering at the rough interface, dropping the calculated transmission coefficient from 0.74 down to 0.15. This transport degradation is driven by severe acoustic impedance mismatch and localized interface vibrational modes. The overall interfacial thermal conductance was calculated to decrease by 48.0% when the interface defect density scaled from 1.0% to 5.0% at 300.0 K. These molecular dynamics calculations clarify the atomic-scale paths limiting heat carrier propagation, helping engineers design targeted thermal management interfaces for high-power electronics.
Keywords: Thermal conductance; phonon wavepacket; molecular dynamics; interface defects; silicon-gallium nitride; electronics cooling
Manuscript Timeline: Received: October 12, 2024; Revised: November 22, 2024; Accepted: December 10, 2024; Published: January 15, 2025
Citation: Meyer, D. W., & Mueller, H. L. (2025). Thermal Dispersion Parameters and Phonon Scattering Dynamics across Silicon-Gallium Nitride Heterojunctions. International Journal of Physics, 16(1), 1–8.