International Journal of Physics | Vol. 10, No. 12, December 2019 | pp. 89–96
DOI: 10.46882/2019/IJP/000116
Research Article
Title: Fluid Velocity Mapping and Magnetic Reconnection Rates in the Solar Corona via High-Resolution Extreme Ultraviolet Telescopes
Names of Authors: G. R. Davies¹, M. T. Al-Saeed²
Authors’ Affiliations:
¹ School of Physics and Astronomy, University of St Andrews, St Andrews, UK
² Department of Physics, Faculty of Science, Kuwait University, Safat, Kuwait
Abstract: Magnetic reconnection is the primary physical process driving explosive energy releases in solar atmospheric plasma, heating material to millions of Kelvin and accelerating coronal mass ejections. This paper evaluates fluid velocity mapping and quantifies local magnetic reconnection rates within an X-class solar flare event. We utilized high-resolution spectroscopic data from space-based extreme ultraviolet (EUV) channels tracking highly ionized iron lines (Fe XVI and Fe XXIV). Differential affine velocity estimator algorithms were deployed to construct two-dimensional velocity fields of plasma inflows and outflows surrounding the current sheet. The empirical measurements reveal systematic plasma inflows moving at 18.2 km/s, while directed outflows reach velocities of 285.0 km/s along the coronal loop headers. 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 localized turbulent transport. Spectroscopic line-broadening analysis indicates localized turbulent temperatures peaking at 9.2 MK within the diffusion region, confirming intense localized viscous dissipation. These imaging diagnostics provide direct observational parameters for refining magnetohydrodynamic models of solar coronal heating loops.
Keywords: Solar corona; magnetic reconnection; extreme ultraviolet; plasma dynamics; solar flares; magnetohydrodynamics
Manuscript Timeline: Received: August 18, 2019; Revised: October 10, 2019; Accepted: November 02, 2019; Published: December 16, 2019
Citation: Davies, G. R., & Al-Saeed, M. T. (2019). Fluid Velocity Mapping and Magnetic Reconnection Rates in the Solar Corona via High-Resolution Extreme Ultraviolet Telescopes. International Journal of Physics, 10(12), 89–96.
International Journal of Physics | Vol. 10, No. 11, November 2019 | pp. 81–88
DOI: 10.46882/2019/IJP/000115
Research Article
Title: Optical Properties and Exciton-Polariton Dynamics of Monolayer Molybdenum Disulfide on Dielectric Bragg Reflectors
Names of Authors: Y. S. Kim¹, C. M. Brauer²
Authors’ Affiliations:
¹ Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
² Institut für Physik, Humboldt-Universität zu Berlin, Berlin, Germany
Abstract: Monolayer transition metal dichalcogenides have attracted significant interest due to their strong light-matter interactions and potential for nanoscale valleytronic devices. This study characterises the optical properties and exciton-polariton dynamics of monolayer molybdenum disulfide (MoS²) integrated onto dielectric silicon/silicon dioxide Bragg reflectors. The monolayer flakes were synthesized via chemical vapor deposition and transferred onto the nanostructured substrates using an optimized dry-transfer technique. We performed micro-photoluminescence and angle-resolved reflectivity measurements under mechanical tensile strains from 0.0% to 1.8% at a room temperature of 300 K. The unstrained monolayer coupled to the microcavity exhibits a strong Rabi splitting of 48.2 meV, confirming the transition into the strong light-matter coupling regime. Applying a 1.2% tensile strain shifts the exciton resonance energy from 1.85 eV to 1.78 eV, yielding a strain tuning factor of 58.3 meV/% strain. Time-resolved photoluminescence spectroscopy revealed a shortened polariton decay lifetime, dropping from 14.5 ps down to 4.2 ps due to the microcavity Purcell effect. Our numerical models confirm that the localized electromagnetic field confinement within the mirrors increases the exciton-photon coupling rate by 40.0%. These findings demonstrate that cavity-integrated strain engineering offers an effective route for controlling exciton-polariton states in thin-film optoelectronic architectures.
Keywords: Molybdenum disulfide; Bragg reflectors; photoluminescence; exciton-polariton; tensile strain; light-matter coupling
Manuscript Timeline: Received: July 12, 2019; Revised: September 04, 2019; Accepted: September 22, 2019; Published: November 12, 2019
Citation: Kim, Y. S., & Brauer, C. M. (2019). Optical Properties and Exciton-Polariton Dynamics of Monolayer Molybdenum Disulfide on Dielectric Bragg Reflectors. International Journal of Physics, 10(11), 81–88.
International Journal of Physics | Vol. 10, No. 10, October 2019 | pp. 73–80
DOI: 10.46882/2019/IJP/000114
Research Article
Title: Optical Soliton Perturbations and Wave Collapse Arrest in Non-Local Graphene Metamaterials
Names of Authors: S. H. Zhang¹, Y. S. Kim²
Authors’ Affiliations: ¹Department of Physics, Tsinghua University, Beijing, China; ²Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
Abstract: Developing non-linear optical configurations that can stabilize ultra-short pulse propagation or safely arrest high-power beam collapse is an essential goal for laser engineering and high-speed data links. This paper solves the generalized non-linear Schrödinger equation governing optical soliton perturbations and tracks wave collapse dynamics inside non-local graphene-based metamaterials. The mathematical model integrates higher-order perturbation terms, including third-order dispersion, self-steepening, and delayed Raman response steps. We applied the inverse scattering transform method combined with a multiple-scale perturbation routine to derive analytical solutions for stable single-solitons and breathers. The results demonstrate that a high degree of spatial non-locality effectively suppresses catastrophic self-focusing collapse, stabilizing two-dimensional structures that are unstable in local Kerr devices. The modulation instability growth rate was calculated against variable perturbation frequencies, highlighting a maximum gain coefficient of g = 2.76 cm^-1 under an input beam intensity of 1.6 kW/cm². Expanding the non-locality parameter from 0.6 mm to 3.5 mm reduces the peak instability gain by 64.0%, preventing pulse fragmentation.
Keywords: Nonlinear optics; spatial solitons; nonlinear Schrödinger equation; modulational instability; non-local media; wave collapse
Manuscript Timeline: Received: June 02, 2019; Revised: July 29, 2019; Accepted: August 25, 2019; Published: October 08, 2019
Citation: Zhang, S. H., & Kim, Y. S. (2019). Optical Soliton Perturbations and Wave Collapse Arrest in Non-Local Graphene Metamaterials. International Journal of Physics, 10(10), 73–80.
International Journal of Physics | Vol. 10, No. 9, September 2019 | pp. 65–72
DOI: 10.46882/2019/IJP/000113
Research Article
Title: Superconducting Gap Profiles and Interband Spin Fluctuations in Electron-Doped Pnictide CaFe2As2 Crystals
Names of Authors: I. R. Sokolov¹, V. I. Morozov²
Authors’ Affiliations: ¹Kapitza Institute for Physical Problems, Russian Academy of Sciences, Moscow, Russia; ²Institute 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. We synthesized high-quality single crystals of electron-doped CaFe2As2 using a specialized self-flux crystal growth routine under pressure. The internal superconducting gap profiles 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 parameters (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. The large gap magnitude was measured at Δ1 = 7.1 meV on the inner hole-like Fermi surface 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 profiles; photoemission spectroscopy; London penetration depth; pairing symmetry; spin fluctuations
Manuscript Timeline: Received: May 14, 2019; Revised: July 08, 2019; Accepted: August 03, 2019; Published: September 10, 2019
Citation: Sokolov, I. R., & Morozov, V. I. (2019). Superconducting Gap Profiles and Interband Spin Fluctuations in Electron-Doped Pnictide CaFe2As2 Crystals. International Journal of Physics, 10(9), 65–72.
International Journal of Physics | Vol. 10, No. 8, August 2019 | pp. 57–64
DOI: 10.46882/2019/IJP/000112
Research Article
Title: Squeezed Vacuum State Routing and Quantum Decoherence Metrics in Ring-Resonator Optical Photonic Circuits
Names of Authors: A. M. Ross¹, L. K. Rousseau²
Authors’ Affiliations: ¹Department of Physics, University of Queensland, Brisbane, QLD 4072, Australia; ²Laboratoire de Physique des Plasmas, École Polytechnique, Palaiseau, France
Abstract: Routing non-classical states of light with high precision across integrated chips is a fundamental operational necessity for building distributed quantum computing arrays and cryptography nodes. This study models continuous-wave squeezed vacuum state routing and evaluates quantum decoherence metrics inside integrated ring-resonator optical photonic circuits. We solved the spatial quantum stochastic Schrödinger equations using an algebraic operator framework that accounts for localized evanescent coupling gaps, material scattering 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 cascaded four-ring network. The calculations demonstrate that introducing a minor 2.0% fabrication asymmetry across the ring margins induces destructive phase shifts, dropping the squeezed noise limit from 8.2 dB down to 2.5 dB at the exit port. To protect state purity, we simulated an active phase-stabilization feedback loop that tracks the relative local oscillator phase parameters in real-time. The optimized circuit configuration restored the squeezing level to 7.0 dB, yielding a state fidelity calculation of 95.2% ± 0.3%. These findings assist in minimizing state degradation across complex quantum networks.
Keywords: Quantum optics; squeezed states; ring resonators; integrated photonics; quantum decoherence; phase stabilization
Manuscript Timeline: Received: April 15, 2019; Revised: June 02, 2019; Accepted: June 22, 2019; Published: August 14, 2019
Citation: Ross, A. M., & Rousseau, L. K. (2019). Squeezed Vacuum State Routing and Quantum Decoherence Metrics in Ring-Resonator Optical Photonic Circuits. International Journal of Physics, 10(8), 57–64.
International Journal of Physics | Vol. 10, No. 7, July 2019 | pp. 49–56
DOI: 10.46882/2019/IJP/000111
Research Article
Title: Finite Element Modeling of Acoustic Cloaking and Wave Deflection in Anisotropic Piezocomposite Lattices
Names of Authors: P. J. O’Connor¹, S. H. Zhang²
Authors’ Affiliations: ¹Department of Civil and Environmental Engineering, University College Cork, Cork, Ireland; ²Department of Physics, Tsinghua University, Beijing, China
Abstract: Steering elastic paths in dense underwater or aerospace environments is crucial for acoustic hiding systems, smart acoustic isolation barriers, and structural wave management components. This study presents a finite element modeling framework to simulate acoustic cloaking and acoustic wave deflection profiles within anisotropic piezocomposite structural lattices. The metamaterial configuration uses coordinate-transformation methods applied to Biot's dynamic equations to calculate the specific distributions of density tensors and elastic modulus matrices. We executed numerical scattering operations across an acoustic frequency spectrum spanning 15.0 kHz to 90.0 kHz. The computational models show that a cylindrical shell cloak composed of 32 concentric sub-wavelength piezoelectric layers routes an incident wave around a central cavity. This active structure cuts the total scattering cross-section by 86.0% at a design marker of 45.0 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 target sound velocity profiles. Experimental verification used 3D-printed perforated piezoceramic rings immersed in a testing fluid tank. The measured acoustic pressure mappings matched the simulated fields within a tight ±4.8% error margin.
Keywords: Acoustic metamaterials; finite element modeling; acoustic cloaking; Biot's theory; piezocomposites; wave deflection
Manuscript Timeline: Received: March 20, 2019; Revised: May 05, 2019; Accepted: May 28, 2019; Published: July 15, 2019
Citation: O’Connor, P. J., & Zhang, S. H. (2019). Finite Element Modeling of Acoustic Cloaking and Wave Deflection in Anisotropic Piezocomposite Lattices. International Journal of Physics, 10(7), 49–56.