Pub Date : 2025-11-02DOI: 10.1016/j.cjph.2025.10.025
Muhammad Waheed Aslam , Abrar Ahmad Zafar , Muhammad Naeem Aslam , Salman Saleem , Abdelhalim Hasnaoui
We investigate a neutrino mass model based on Δ(27) discrete flavor symmetry and the type I seesaw mechanism, which is formulated by extending the Standard Model (SM) with additional Higgs doublets, right-handed neutrinos, and scalar triplets. We analyze the model by using particle swarm optimization (PSO) and neural network algorithm (NNA). The working efficiencies of both meta-heuristic optimization techniques are compared as well. The neutrino oscillation parameters are optimized, which are consistent with recent experimental data. Our analysis also aligns with Planck cosmological constraints on the sum of neutrino masses. Key predictions include neutrino masses, UPMNS matrix, effective neutrino masses for neutrinoless double beta decay, beta decay, Dirac and Majorana CP violation phases, and Jarlskog invariant, offering testable implications.
{"title":"Optimizing neutrino mass predictions with particle swarm optimization and neural network algorithm under SU(2)L × Δ(27) × Z2 symmetry","authors":"Muhammad Waheed Aslam , Abrar Ahmad Zafar , Muhammad Naeem Aslam , Salman Saleem , Abdelhalim Hasnaoui","doi":"10.1016/j.cjph.2025.10.025","DOIUrl":"10.1016/j.cjph.2025.10.025","url":null,"abstract":"<div><div>We investigate a neutrino mass model based on Δ(27) discrete flavor symmetry and the type I seesaw mechanism, which is formulated by extending the Standard Model (SM) with additional Higgs doublets, right-handed neutrinos, and scalar triplets. We analyze the model by using particle swarm optimization (PSO) and neural network algorithm (NNA). The working efficiencies of both meta-heuristic optimization techniques are compared as well. The neutrino oscillation parameters are optimized, which are consistent with recent experimental data. Our analysis also aligns with Planck cosmological constraints on the sum of neutrino masses. Key predictions include neutrino masses, <em>U<sub>PMNS</sub></em> matrix, effective neutrino masses for neutrinoless double beta decay, beta decay, Dirac and Majorana CP violation phases, and Jarlskog invariant, offering testable implications.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 964-980"},"PeriodicalIF":4.6,"publicationDate":"2025-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-30DOI: 10.1016/j.cjph.2025.10.028
Zhiqiang Cai , Wenming Wei
This study aims to investigate the impact of bleb formation on intracranial aneurysm hemodynamics using patient-specific computational fluid dynamics (CFD) models. Three anterior cerebral artery aneurysm cases (two unruptured, one ruptured) were analyzed using CFD simulations based on patient-derived geometries. Each aneurysm was modeled in three configurations: (1) normal geometry without blebs, (2) with three artificially added blebs, and (3) with a 50 % radius reduction on each bleb to simulate localized curvature enhancement. Pulsatile flow conditions were applied using physiological inlet mass flow and outlet pressure profiles. Blood was modeled as a non-Newtonian fluid using the Casson model. Key hemodynamic parameters—including wall shear stress (WSS), oscillatory shear index (OSI), pressure, and intra-sac velocity—were evaluated across all models. Our results indicate that the addition of blebs led to localized reductions in minimum WSS, elevated OSI, and decreased intra-sac velocity, particularly in the reduced-radius models. The results suggest that bleb regions are hemodynamically distinct and potentially more vulnerable to rupture due to low WSS, high OSI, and flow stagnation. These findings support the hypothesis that blebs contribute to aneurysm instability through adverse mechanobiological conditions and highlight the need to include bleb morphology in patient-specific rupture risk assessments.
{"title":"Computational analysis of bleb-induced hemodynamic disturbances in cerebral aneurysms","authors":"Zhiqiang Cai , Wenming Wei","doi":"10.1016/j.cjph.2025.10.028","DOIUrl":"10.1016/j.cjph.2025.10.028","url":null,"abstract":"<div><div>This study aims to investigate the impact of bleb formation on intracranial aneurysm hemodynamics using patient-specific computational fluid dynamics (CFD) models. Three anterior cerebral artery aneurysm cases (two unruptured, one ruptured) were analyzed using CFD simulations based on patient-derived geometries. Each aneurysm was modeled in three configurations: (1) normal geometry without blebs, (2) with three artificially added blebs, and (3) with a 50 % radius reduction on each bleb to simulate localized curvature enhancement. Pulsatile flow conditions were applied using physiological inlet mass flow and outlet pressure profiles. Blood was modeled as a non-Newtonian fluid using the Casson model. Key hemodynamic parameters—including wall shear stress (WSS), oscillatory shear index (OSI), pressure, and intra-sac velocity—were evaluated across all models. Our results indicate that the addition of blebs led to localized reductions in minimum WSS, elevated OSI, and decreased intra-sac velocity, particularly in the reduced-radius models. The results suggest that bleb regions are hemodynamically distinct and potentially more vulnerable to rupture due to low WSS, high OSI, and flow stagnation. These findings support the hypothesis that blebs contribute to aneurysm instability through adverse mechanobiological conditions and highlight the need to include bleb morphology in patient-specific rupture risk assessments.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 834-849"},"PeriodicalIF":4.6,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The investigation of nonlinear jet stability in presence of a periodic electric field (EF) is crucial in many applications like electrospray technology, inkjet printing, and microfluidic devices. This work facilitates process optimization and introduces novel fluid operation capabilities. Viscose fluids in porous media are fully saturated. The viscous potential theory (VPT) is planned to simplify the mathematical complexity. A nonlinear characteristic dispersion equation is produced by applying the appropriate nonlinear boundary conditions (BCs) to the linearized equations of motion. This equation governs the amplitude of the interface displacement of the surface waves. An inclusion of non-dimensional analysis led to certification of some widely recognized physical quantities. The non-perturbative approach (NPA) is the foundation of the current work. The basis of this approach is He's frequency formulation (HFF). The weakly nonlinear oscillator of ordinary differential equation (ODE) in the kernel is transformed into a compatible linear one. The nonlinear ODE is checked against the linear one using Mathematica Software (MS). Consequently, the stability technique primarily concerns the linear ODE, in which the stability criterion is estimated. The influence of many non-dimensional physical parameters on the stability profile is shown through a set of diagrams. To provide an approximate solution, the chaotic behavior of the system is examined. Additionally, the external resonance case is examined to derive modulation equations and establish the solvability condition. Various polar plots are included to verify the stability of the derived solutions. Furthermore, chaotic behavior of the system is analyzed through bifurcation diagrams, phase portraits, and Poincaré maps.
{"title":"A novel assessment of nonlinear stability of a liquid jet activated by uniform/periodic electric field","authors":"Galal M. Moatimid , Mona A.A. Mohamed , Khaled Elagamy , M.K. Abohamer","doi":"10.1016/j.cjph.2025.10.026","DOIUrl":"10.1016/j.cjph.2025.10.026","url":null,"abstract":"<div><div>The investigation of nonlinear jet stability in presence of a periodic electric field (EF) is crucial in many applications like electrospray technology, inkjet printing, and microfluidic devices. This work facilitates process optimization and introduces novel fluid operation capabilities. Viscose fluids in porous media are fully saturated. The viscous potential theory (VPT) is planned to simplify the mathematical complexity. A nonlinear characteristic dispersion equation is produced by applying the appropriate nonlinear boundary conditions (BCs) to the linearized equations of motion. This equation governs the amplitude of the interface displacement of the surface waves. An inclusion of non-dimensional analysis led to certification of some widely recognized physical quantities. The non-perturbative approach (NPA) is the foundation of the current work. The basis of this approach is He's frequency formulation (HFF). The weakly nonlinear oscillator of ordinary differential equation (ODE) in the kernel is transformed into a compatible linear one. The nonlinear ODE is checked against the linear one using Mathematica Software (MS). Consequently, the stability technique primarily concerns the linear ODE, in which the stability criterion is estimated. The influence of many non-dimensional physical parameters on the stability profile is shown through a set of diagrams. To provide an approximate solution, the chaotic behavior of the system is examined. Additionally, the external resonance case is examined to derive modulation equations and establish the solvability condition. Various polar plots are included to verify the stability of the derived solutions. Furthermore, chaotic behavior of the system is analyzed through bifurcation diagrams, phase portraits, and Poincaré maps.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 810-833"},"PeriodicalIF":4.6,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-29DOI: 10.1016/j.cjph.2025.10.023
Ghulam Rasool , Muhammad Ijaz Khan , F.F. Al-Harbi
This study presents an extended linear and nonlinear stability analysis of double-diffusive nanofluid convection in an inclined porous medium, incorporating nonlinear inertial effects via the Forchheimer drag term. The governing equations are formulated using a generalized Darcy-Forchheimer model with thermal and solutal buoyancy forces projected along the inclined axis. Linear stability is assessed via a normal mode analysis, leading to a generalized eigenvalue problem solved numerically using finite difference discretization. Nonlinear energy stability is investigated through an integral energy method, yielding conservative thresholds for the onset of convective instability. Comprehensive parametric studies reveal the influence of Darcy number, Lewis number, and inclination angle on both thermal and solutal Rayleigh thresholds. Results show that nonlinear thresholds exhibit sharp maxima near , highlighting the geometric suppression of vertical buoyancy. The Forchheimer term consistently enhances stability, especially at low permeability and high inclination. These insights are critical for thermal management and flow control in porous-layer energy systems.
{"title":"Linear and nonlinear stability analysis of double-diffusive nanofluid convection in an inclined porous medium with Forchheimer drag","authors":"Ghulam Rasool , Muhammad Ijaz Khan , F.F. Al-Harbi","doi":"10.1016/j.cjph.2025.10.023","DOIUrl":"10.1016/j.cjph.2025.10.023","url":null,"abstract":"<div><div>This study presents an extended linear and nonlinear stability analysis of double-diffusive nanofluid convection in an inclined porous medium, incorporating nonlinear inertial effects via the Forchheimer drag term. The governing equations are formulated using a generalized Darcy-Forchheimer model with thermal and solutal buoyancy forces projected along the inclined axis. Linear stability is assessed via a normal mode analysis, leading to a generalized eigenvalue problem solved numerically using finite difference discretization. Nonlinear energy stability is investigated through an integral energy method, yielding conservative thresholds for the onset of convective instability. Comprehensive parametric studies reveal the influence of Darcy number, Lewis number, and inclination angle on both thermal and solutal Rayleigh thresholds. Results show that nonlinear thresholds exhibit sharp maxima near <span><math><mrow><mi>β</mi><mo>=</mo><msup><mn>90</mn><mo>∘</mo></msup></mrow></math></span>, highlighting the geometric suppression of vertical buoyancy. The Forchheimer term consistently enhances stability, especially at low permeability and high inclination. These insights are critical for thermal management and flow control in porous-layer energy systems.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 289-307"},"PeriodicalIF":4.6,"publicationDate":"2025-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<div><div>Using the first-principles exact muffin-tin orbital method combined with the coherent potential approximation, we have systematically investigated the correlations between atomic and magnetic ordering configurations and the martensitic transformation (MT), as well as the mechanical properties of all-<em>d</em>-metal <span><math><msub><mi>X</mi><mn>2</mn></msub></math></span>Mn<span><math><mi>Z</mi></math></span> (<em>X</em>=Ni, Cu, Zn, Pd, Pt, and Au; <em>Z</em>=Ti and V) Heusler shape memory alloys. Our results show that in their cubic phase, the <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span> (XA) structure is relatively more stable in the ferromagnetic (paramagnetic) state, as well as for the <em>Z</em>=Ti (V) alloys. Except for Au<span><math><msub><mrow></mrow><mn>2</mn></msub></math></span>MnTi, all these alloys can undergo the MT from <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span> to body-centered tetragonal (BCT), and they are also expected to exhibit significant magnetocaloric, elastocaloric, and barocaloric effects. When <em>X</em>=Ni, Pd, and Pt, their BCT structure can further transform into a simple tetragonal (ST) one with <span><math><mrow><mi>c</mi><mo>/</mo><mi>a</mi><mo>≈</mo><mn>1</mn></mrow></math></span>, i.e., a so-called face-centered cubic (FCC) structure. Both their <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span><span><math><mo>→</mo></math></span>BCT and BCT<span><math><mo>→</mo></math></span>ST transitions are preferred by the antiferromagnetic coupling interactions between Mn and <em>Z</em> atoms, and the successive transitions can even be achieved solely by decreasing the total magnetic moment in each <em>X</em><span><math><mo>≠</mo></math></span>Zn alloy. The Mn-<em>Z</em> disorder suppresses their MT of <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span><span><math><mo>→</mo></math></span>BCT but dominates the BCT<span><math><mo>→</mo></math></span>ST transition, favoring the improvement of their martensite’s ductility. In most of the alloys, the presence of vacancies also disfavors their MT. The coexistence of Mn-<em>Z</em> and <em>X</em>-Mn disorders can cause their cubic phase to decompose and become more brittle. In <span><math><msub><mi>X</mi><mn>2</mn></msub></math></span>MnGa<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span><span><math><msub><mi>Z</mi><mi>x</mi></msub></math></span> quaternary alloys with appropriate <em>Z</em>-doping, their MT temperatures and ductile properties may both be effectively improved when <em>X</em>=Ni and Pt; for <em>X</em>=Cu and Zn, the FCC phase can also be prevented from precipitating. The hybridization between the <span><math><mrow><mi>X</mi><mo>_</mo><mi>d</mi></mrow></math></span> and <span><math><mrow><mi>Z</mi><mo>_</mo><mi>d</mi></mrow></math></span> electrons near the Fermi level p
{"title":"Correlations between atomic and magnetic disorders with the martensitic transformation and mechanical properties of all-d-metal Heusler shape memory alloys","authors":"Chun-Mei Li, Yu-Tong Liu, Zi-Ran Li, Ren-Zhong Huang","doi":"10.1016/j.cjph.2025.10.024","DOIUrl":"10.1016/j.cjph.2025.10.024","url":null,"abstract":"<div><div>Using the first-principles exact muffin-tin orbital method combined with the coherent potential approximation, we have systematically investigated the correlations between atomic and magnetic ordering configurations and the martensitic transformation (MT), as well as the mechanical properties of all-<em>d</em>-metal <span><math><msub><mi>X</mi><mn>2</mn></msub></math></span>Mn<span><math><mi>Z</mi></math></span> (<em>X</em>=Ni, Cu, Zn, Pd, Pt, and Au; <em>Z</em>=Ti and V) Heusler shape memory alloys. Our results show that in their cubic phase, the <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span> (XA) structure is relatively more stable in the ferromagnetic (paramagnetic) state, as well as for the <em>Z</em>=Ti (V) alloys. Except for Au<span><math><msub><mrow></mrow><mn>2</mn></msub></math></span>MnTi, all these alloys can undergo the MT from <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span> to body-centered tetragonal (BCT), and they are also expected to exhibit significant magnetocaloric, elastocaloric, and barocaloric effects. When <em>X</em>=Ni, Pd, and Pt, their BCT structure can further transform into a simple tetragonal (ST) one with <span><math><mrow><mi>c</mi><mo>/</mo><mi>a</mi><mo>≈</mo><mn>1</mn></mrow></math></span>, i.e., a so-called face-centered cubic (FCC) structure. Both their <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span><span><math><mo>→</mo></math></span>BCT and BCT<span><math><mo>→</mo></math></span>ST transitions are preferred by the antiferromagnetic coupling interactions between Mn and <em>Z</em> atoms, and the successive transitions can even be achieved solely by decreasing the total magnetic moment in each <em>X</em><span><math><mo>≠</mo></math></span>Zn alloy. The Mn-<em>Z</em> disorder suppresses their MT of <span><math><mrow><mi>L</mi><msub><mn>2</mn><mn>1</mn></msub></mrow></math></span><span><math><mo>→</mo></math></span>BCT but dominates the BCT<span><math><mo>→</mo></math></span>ST transition, favoring the improvement of their martensite’s ductility. In most of the alloys, the presence of vacancies also disfavors their MT. The coexistence of Mn-<em>Z</em> and <em>X</em>-Mn disorders can cause their cubic phase to decompose and become more brittle. In <span><math><msub><mi>X</mi><mn>2</mn></msub></math></span>MnGa<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span><span><math><msub><mi>Z</mi><mi>x</mi></msub></math></span> quaternary alloys with appropriate <em>Z</em>-doping, their MT temperatures and ductile properties may both be effectively improved when <em>X</em>=Ni and Pt; for <em>X</em>=Cu and Zn, the FCC phase can also be prevented from precipitating. The hybridization between the <span><math><mrow><mi>X</mi><mo>_</mo><mi>d</mi></mrow></math></span> and <span><math><mrow><mi>Z</mi><mo>_</mo><mi>d</mi></mrow></math></span> electrons near the Fermi level p","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 778-792"},"PeriodicalIF":4.6,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-24DOI: 10.1016/j.cjph.2025.10.022
Vemula Rajesh , Hakan F. Öztop
In this paper, a comprehensive computational study is carried out to explore the phase-change dynamics and conjugate heat transfer in a chamber filled with NEPCM-water nanofluid. The chamber features curved (concave type) thick solid walls, and the coupled heat transfer between the solid and fluid regions is modelled using the robust finite element method. The effect of key dimensionless parameters including the thermal conductivity ratio (), Stefan number (Ste), Rayleigh number (Ra), NEPCM nanoparticle volume fraction (ϕ), and fusion temperature () is studied on streamlines, isotherms, and heat capacity contours along with average Nusselt number. The results reveal that higher Rayleigh numbers and lower Stefan numbers enhance natural convection and broaden NEPCM activation zones. An intermediate fusion temperature of = 0.3 consistently yields optimal thermal performance by aligning the melting range with dominant thermal gradients across all conductivity ratios. Increasing NEPCM volume fraction leads to a uniform rise in average Nusselt number, while the balanced conductivity case ( = 1) enables the most effective utilization of latent heat. These findings provide critical insights for optimizing NEPCM-based thermal energy storage and passive cooling systems in enclosures with complex thermal boundaries.
{"title":"Conjugate heat transfer and melting behaviour of Nano particle added phase change materials in a thick concave walled chamber","authors":"Vemula Rajesh , Hakan F. Öztop","doi":"10.1016/j.cjph.2025.10.022","DOIUrl":"10.1016/j.cjph.2025.10.022","url":null,"abstract":"<div><div>In this paper, a comprehensive computational study is carried out to explore the phase-change dynamics and conjugate heat transfer in a chamber filled with NEPCM-water nanofluid. The chamber features curved (concave type) thick solid walls, and the coupled heat transfer between the solid and fluid regions is modelled using the robust finite element method. The effect of key dimensionless parameters including the thermal conductivity ratio (<span><math><msub><mi>R</mi><mi>k</mi></msub></math></span>), Stefan number (Ste), Rayleigh number (Ra), NEPCM nanoparticle volume fraction (ϕ), and fusion temperature (<span><math><msub><mi>θ</mi><mi>f</mi></msub></math></span>) is studied on streamlines, isotherms, and heat capacity contours along with average Nusselt number. The results reveal that higher Rayleigh numbers and lower Stefan numbers enhance natural convection and broaden NEPCM activation zones. An intermediate fusion temperature of <span><math><msub><mi>θ</mi><mi>f</mi></msub></math></span> = 0.3 consistently yields optimal thermal performance by aligning the melting range with dominant thermal gradients across all conductivity ratios. Increasing NEPCM volume fraction leads to a uniform rise in average Nusselt number, while the balanced conductivity case (<span><math><msub><mi>R</mi><mi>k</mi></msub></math></span> = 1) enables the most effective utilization of latent heat. These findings provide critical insights for optimizing NEPCM-based thermal energy storage and passive cooling systems in enclosures with complex thermal boundaries.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 874-899"},"PeriodicalIF":4.6,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1016/j.cjph.2025.10.020
Dong Wei , Gaofu Guo , Heng Yu , Dengrui Zhao , XuanFeng Lv , Yi Li , Yaqiang Ma , Shaoqian Yin , Yanan Tang , Xianqi Dai
Monoclinic gallium oxide (β-Ga2O3) is a promising ultra-wide-bandgap semiconductor, yet its p-type conduction is limited by strong hole localization due to self-trapped polaron formation. During the epitaxial growth, lattice mismatch and growth inhomogeneity inevitably introduce interface defects, such as dislocations and twin boundaries. The effects of these defects on electronic properties and hole transport mechanisms are not yet fully clarified. To address this, we systematically investigate how interfacial defects impact the electronic properties of β-Ga2O3. The interfacial symmetry breaking and local lattice distortions modify the O coordination, leading to shallow defect states dominated by O-2p (pz and py) orbitals. The electronic states arising from interface defects can interact with localized hole states in the host material, which may lead to the delocalization of holes. The interfacial symmetry breaking inhibits the formation of self-trapped hole polarons by reducing the availability of delocalized states near the Fermi level. This finding provides theoretical insights into how defect-assisted orbital reconfiguration may be exploited to overcome transport limitations in wide-bandgap oxides.
{"title":"Effect of interfacial defects on the electronic properties of β-Ga2O3: coupling of lattice distortions and electron localized states","authors":"Dong Wei , Gaofu Guo , Heng Yu , Dengrui Zhao , XuanFeng Lv , Yi Li , Yaqiang Ma , Shaoqian Yin , Yanan Tang , Xianqi Dai","doi":"10.1016/j.cjph.2025.10.020","DOIUrl":"10.1016/j.cjph.2025.10.020","url":null,"abstract":"<div><div>Monoclinic gallium oxide (β-Ga<sub>2</sub>O<sub>3</sub>) is a promising ultra-wide-bandgap semiconductor, yet its p-type conduction is limited by strong hole localization due to self-trapped polaron formation. During the epitaxial growth, lattice mismatch and growth inhomogeneity inevitably introduce interface defects, such as dislocations and twin boundaries. The effects of these defects on electronic properties and hole transport mechanisms are not yet fully clarified. To address this, we systematically investigate how interfacial defects impact the electronic properties of β-Ga<sub>2</sub>O<sub>3</sub>. The interfacial symmetry breaking and local lattice distortions modify the O coordination, leading to shallow defect states dominated by O-2<em>p</em> (<em>p<sub>z</sub></em> and <em>p<sub>y</sub></em>) orbitals. The electronic states arising from interface defects can interact with localized hole states in the host material, which may lead to the delocalization of holes. The interfacial symmetry breaking inhibits the formation of self-trapped hole polarons by reducing the availability of delocalized states near the Fermi level. This finding provides theoretical insights into how defect-assisted orbital reconfiguration may be exploited to overcome transport limitations in wide-bandgap oxides.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 729-740"},"PeriodicalIF":4.6,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1016/j.cjph.2025.10.015
Jia-Rui Li , Peng-Fei Zang , Cui Jiang , Kai Du , Xue-Feng Dai , Wei-Jiang Gong
We propose a one-dimensional non-Hermitian unidirectional Su-Schrieffer-Heeger (uSSH) structure with long-range hopping terms, investigating various phase transition phenomena, and the manipulation of quantum states in the system. Through theoretical analysis and numerical calculations, we find that the system exhibits rich phase transition phenomena, including pseudo-Hermitian symmetry transitions, topological phase transitions, and skin effect transitions. Meanwhile, the long-range hopping induces a novel bipolar skin effect in the system and leads to non-trivial localization properties of the topological zero-energy modes. Namely, one zero-energy mode is localized in a direction similar to that of the skin states, while the other is localized in the opposite direction. These results demonstrate that long-range hopping terms can effectively achieve spatial separation of topological states from the skin states. Therefore, our study reveals the crucial role of long-range hopping terms in driving quantum phase transitions in the one-dimensional uSSH structure, providing new insights into the phase transition mechanisms in non-Hermitian topological systems.
{"title":"Quantum-state manipulation of one-dimensional long-range non-Hermitian unidirectional Su-Schrieffer-Heeger structure","authors":"Jia-Rui Li , Peng-Fei Zang , Cui Jiang , Kai Du , Xue-Feng Dai , Wei-Jiang Gong","doi":"10.1016/j.cjph.2025.10.015","DOIUrl":"10.1016/j.cjph.2025.10.015","url":null,"abstract":"<div><div>We propose a one-dimensional non-Hermitian unidirectional Su-Schrieffer-Heeger (uSSH) structure with long-range hopping terms, investigating various phase transition phenomena, and the manipulation of quantum states in the system. Through theoretical analysis and numerical calculations, we find that the system exhibits rich phase transition phenomena, including pseudo-Hermitian symmetry transitions, topological phase transitions, and skin effect transitions. Meanwhile, the long-range hopping induces a novel bipolar skin effect in the system and leads to non-trivial localization properties of the topological zero-energy modes. Namely, one zero-energy mode is localized in a direction similar to that of the skin states, while the other is localized in the opposite direction. These results demonstrate that long-range hopping terms can effectively achieve spatial separation of topological states from the skin states. Therefore, our study reveals the crucial role of long-range hopping terms in driving quantum phase transitions in the one-dimensional uSSH structure, providing new insights into the phase transition mechanisms in non-Hermitian topological systems.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 670-683"},"PeriodicalIF":4.6,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-20DOI: 10.1016/j.cjph.2025.10.019
Tao Chen, Yimai Huang
The design of terahertz (THz) metamaterial sensors often involves large parameter spaces and computationally expensive simulations. To address the inefficiency of traditional trial-and-error methods in THz metamaterial sensor design, this study employs a compact and data-efficient modeling method. A dimensionality-reduction strategy based on equivalent circuit modeling is adopted to represent each spectrum using only four circuit parameters (L, C, , ), which are predicted via a backpropagation (BP) neural network. This approach significantly reduces the learning complexity while maintaining high accuracy, achieving a mean absolute error (MAE) of less than 0.01 across the entire transmission spectrum. Furthermore, by integrating the trained network with the NSGA-II multi-objective optimization algorithm, we successfully designed target-oriented metamaterial structures. As a demonstration, a balanced-performance sensor was obtained with a sensitivity of 618 GHz/RIU, absorption above 90 %, and a Q-factor of 14. These results highlight the effectiveness and flexibility of combining physical modeling and machine learning for rapid metamaterial sensor design.
{"title":"Intelligent design of terahertz metamaterial sensors via equivalent circuit dimensionality reduction and multi-objective optimization","authors":"Tao Chen, Yimai Huang","doi":"10.1016/j.cjph.2025.10.019","DOIUrl":"10.1016/j.cjph.2025.10.019","url":null,"abstract":"<div><div>The design of terahertz (THz) metamaterial sensors often involves large parameter spaces and computationally expensive simulations. To address the inefficiency of traditional trial-and-error methods in THz metamaterial sensor design, this study employs a compact and data-efficient modeling method. A dimensionality-reduction strategy based on equivalent circuit modeling is adopted to represent each spectrum using only four circuit parameters (<em>L, C</em>, <span><math><msub><mi>R</mi><mi>s</mi></msub></math></span>, <span><math><msub><mi>R</mi><mtext>LOSS</mtext></msub></math></span>), which are predicted via a backpropagation (BP) neural network. This approach significantly reduces the learning complexity while maintaining high accuracy, achieving a mean absolute error (MAE) of less than 0.01 across the entire transmission spectrum. Furthermore, by integrating the trained network with the NSGA-II multi-objective optimization algorithm, we successfully designed target-oriented metamaterial structures. As a demonstration, a balanced-performance sensor was obtained with a sensitivity of 618 GHz/RIU, absorption above 90 %, and a Q-factor of 14. These results highlight the effectiveness and flexibility of combining physical modeling and machine learning for rapid metamaterial sensor design.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 741-752"},"PeriodicalIF":4.6,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the onset of convective instabilities in a Van der Waals gas within porous media under magnetic fields, emphasizing heat transfer and stability conditions. Both linear and nonlinear instabilities are examined using the Lorentz force framework and the Ginzburg-Landau equation, respectively. Numerical simulations characterize convective motion, temperature variations, and profile deviations, while analytical methods yield the critical Rayleigh number. Results indicate that higher permeability enhances convection and accelerates stabilization, whereas stronger magnetic fields suppress convection and favor conduction-driven heat transfer. Real-gas effects delay instability onset, with attractive intermolecular forces offering stronger stabilization than repulsive ones; the magnetic field’s stabilizing influence becomes more prominent in less permeable media. Additionally, F-test results validate the neural network’s accuracy in reproducing variance behavior, confirming model reliability. These findings contribute valuable insights for improving thermal management and controlling convective stability in practical applications.
{"title":"Onset of convective instabilities in magnetized Van der Waals gas with porous media","authors":"Pavan Kumar Reddy Muduganti , Aparna Podila , Suresh Kumar Raju S , Al-Obaidi RH , Seepana Praveenkumar","doi":"10.1016/j.cjph.2025.10.009","DOIUrl":"10.1016/j.cjph.2025.10.009","url":null,"abstract":"<div><div>This study investigates the onset of convective instabilities in a Van der Waals gas within porous media under magnetic fields, emphasizing heat transfer and stability conditions. Both linear and nonlinear instabilities are examined using the Lorentz force framework and the Ginzburg-Landau equation, respectively. Numerical simulations characterize convective motion, temperature variations, and profile deviations, while analytical methods yield the critical Rayleigh number. Results indicate that higher permeability enhances convection and accelerates stabilization, whereas stronger magnetic fields suppress convection and favor conduction-driven heat transfer. Real-gas effects delay instability onset, with attractive intermolecular forces offering stronger stabilization than repulsive ones; the magnetic field’s stabilizing influence becomes more prominent in less permeable media. Additionally, F-test results validate the neural network’s accuracy in reproducing variance behavior, confirming model reliability. These findings contribute valuable insights for improving thermal management and controlling convective stability in practical applications.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"98 ","pages":"Pages 753-767"},"PeriodicalIF":4.6,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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