Pub Date : 2026-01-07DOI: 10.1016/j.cjph.2026.01.004
Daniil S. Buzin , Pavel S. Pankin , Dmitrii N. Maksimov , Vitaly S. Sutormin , Gavriil A. Romanenko , Rashid G. Bikbaev , Sergey V. Nedelin , Nikita A. Zolotovskii , Igor A. Tambasov , Stepan Ya. Vetrov , Kuo-Ping Chen , Ivan V. Timofeev
A comprehensive approach for simulating lasing dynamics in a liquid crystal based laser is presented. The approach takes into account the transformation of the liquid crystal structure caused by applied voltage. In particular, it allows us to explicitly account for a resonant mode frequency shift in the laser equations. The laser dynamic is described by a set of coupled non-linear differential equations for dye polarizations, population densities and the electromagnetic fields. The proposed model is applied to a photonic crystal - metal microcavity filled with a resonant nematic liquid crystal layer doped with a dye. The calculated lasing spectra governed by external electric field are verified in comparison with measured spectra.
{"title":"Electrically controlled laser generation in a photonic crystal - liquid crystal - metal microcavity","authors":"Daniil S. Buzin , Pavel S. Pankin , Dmitrii N. Maksimov , Vitaly S. Sutormin , Gavriil A. Romanenko , Rashid G. Bikbaev , Sergey V. Nedelin , Nikita A. Zolotovskii , Igor A. Tambasov , Stepan Ya. Vetrov , Kuo-Ping Chen , Ivan V. Timofeev","doi":"10.1016/j.cjph.2026.01.004","DOIUrl":"10.1016/j.cjph.2026.01.004","url":null,"abstract":"<div><div>A comprehensive approach for simulating lasing dynamics in a liquid crystal based laser is presented. The approach takes into account the transformation of the liquid crystal structure caused by applied voltage. In particular, it allows us to explicitly account for a resonant mode frequency shift in the laser equations. The laser dynamic is described by a set of coupled non-linear differential equations for dye polarizations, population densities and the electromagnetic fields. The proposed model is applied to a photonic crystal - metal microcavity filled with a resonant nematic liquid crystal layer doped with a dye. The calculated lasing spectra governed by external electric field are verified in comparison with measured spectra.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 127-140"},"PeriodicalIF":4.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074729","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 : 2026-01-07DOI: 10.1016/j.cjph.2026.01.005
Abhishek Yadav, Punit Kumar
The study of electron acoustic waves (EAWs) and their associated solitary structures in semiconductor quantum plasma doped with nanoparticle clusters has been carried out. The system consists of cold and hot electrons, holes, and stationary ions. The theory has been built using the quantum hydrodynamic (QHD) model. The dispersion relation for EAWs has been set up. To explore nonlinear behaviour, the perturbation technique has been applied, leading to the Korteweg de Vries (KdV) equation. The analysis demonstrates that quantum effects stabilize wave propagation at higher frequencies, while the presence of nanoparticles strongly influence wave dispersion at higher frequencies. Nonlinear analysis shows that solitons in quantum plasma attain higher amplitudes and broader structures due to quantum effects and with the inclusion of nanoparticles.
本文研究了掺杂纳米粒子团簇的半导体量子等离子体中电子声波及其相关的孤立结构。该系统由冷电子、热电子、空穴和固定离子组成。该理论是使用量子流体力学（QHD）模型建立的。建立了ews的色散关系。为了探索非线性行为，应用了微扰技术，得到了Korteweg de Vries （KdV）方程。分析表明，量子效应稳定了高频波的传播，而纳米粒子的存在强烈地影响了高频波的色散。非线性分析表明，由于量子效应和纳米粒子的加入，量子等离子体中的孤子具有更高的振幅和更宽的结构。
{"title":"Electron acoustic solitons in nanoparticle doped semiconductor quantum plasmas","authors":"Abhishek Yadav, Punit Kumar","doi":"10.1016/j.cjph.2026.01.005","DOIUrl":"10.1016/j.cjph.2026.01.005","url":null,"abstract":"<div><div>The study of electron acoustic waves (EAWs) and their associated solitary structures in semiconductor quantum plasma doped with nanoparticle clusters has been carried out. The system consists of cold and hot electrons, holes, and stationary ions. The theory has been built using the quantum hydrodynamic (QHD) model. The dispersion relation for EAWs has been set up. To explore nonlinear behaviour, the perturbation technique has been applied, leading to the Korteweg de Vries (KdV) equation. The analysis demonstrates that quantum effects stabilize wave propagation at higher frequencies, while the presence of nanoparticles strongly influence wave dispersion at higher frequencies. Nonlinear analysis shows that solitons in quantum plasma attain higher amplitudes and broader structures due to quantum effects and with the inclusion of nanoparticles.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 308-322"},"PeriodicalIF":4.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074732","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 : 2026-01-07DOI: 10.1016/j.cjph.2026.01.006
Jing-Run Wei, Wei-Kang Zhang, Zong-Liang Li, Chuan-Kui Wang, Xiao-Xiao Fu
Constructing two-dimensional van der Waals magnetic tunnel junctions with the giant tunneling magnetoresistance effect is crucial towards miniaturized spintronic devices. Herein, we introduce a two-dimensional van der Waals magnetic tunnel junction based on the VSi2N4 half-metal and the Janus MoSiGeN4 semiconductor material, and comprehensively investigate the spintronic transport properties by using density functional theory combined with the non-equilibrium Green's function method. A spin filtering efficiency close to 100% is achieved for the VSi2N4/MoSiGeN4/VSi2N4 magnetic tunnel junction with a parallel magnetic configuration, and, surprisingly, a large tunnel magnetoresistance ratio is obtained. Due to the intrinsic dipole moment of Janus MoSiGeN4, a large tunnel dipole-induced resistance ratio of 6999% is observed in the VSi2N4/bilayer-MoSiGeN4/VSi2N4 van der Waals magnetic tunnel junction at zero bias voltage, and it can be further improved by tuning the bias voltage. Importantly, the high spin filtering efficiency and the large tunneling magnetoresistance ratios are maintained throughout the entire bias voltage range. The large tunneling magnetoresistance effect is attributed to the absence of electron states in both spin-conducting channels near the Fermi level in the antiparallel magnetic configuration. Subsequently, we classify the six distinct magnetic and electric combinations of the magnetic tunnel junctions into four distinguishable storage states. Multilevel data storage is thereby achieved through the cooperative control of magnetic and electrical switching. We demonstrate that the VSi2N4/MoSiGeN4/VSi2N4 and VSi2N4/bilayer-MoSiGeN4/VSi2N4 van der Waals magnetic tunnel junctions are promising candidates for next-generation spintronic devices.
{"title":"Large magnetoresistance and nonvolatile multi-level memory in VSi2N4/MoSiGeN4/VSi2N4 magnetic tunnel junctions","authors":"Jing-Run Wei, Wei-Kang Zhang, Zong-Liang Li, Chuan-Kui Wang, Xiao-Xiao Fu","doi":"10.1016/j.cjph.2026.01.006","DOIUrl":"10.1016/j.cjph.2026.01.006","url":null,"abstract":"<div><div>Constructing two-dimensional van der Waals magnetic tunnel junctions with the giant tunneling magnetoresistance effect is crucial towards miniaturized spintronic devices. Herein, we introduce a two-dimensional van der Waals magnetic tunnel junction based on the VSi<sub>2</sub>N<sub>4</sub> half-metal and the Janus MoSiGeN<sub>4</sub> semiconductor material, and comprehensively investigate the spintronic transport properties by using density functional theory combined with the non-equilibrium Green's function method. A spin filtering efficiency close to 100% is achieved for the VSi<sub>2</sub>N<sub>4</sub>/MoSiGeN<sub>4</sub>/VSi<sub>2</sub>N<sub>4</sub> magnetic tunnel junction with a parallel magnetic configuration, and, surprisingly, a large tunnel magnetoresistance ratio is obtained. Due to the intrinsic dipole moment of Janus MoSiGeN<sub>4</sub>, a large tunnel dipole-induced resistance ratio of 6999% is observed in the VSi<sub>2</sub>N<sub>4</sub>/bilayer-MoSiGeN<sub>4</sub>/VSi<sub>2</sub>N<sub>4</sub> van der Waals magnetic tunnel junction at zero bias voltage, and it can be further improved by tuning the bias voltage. Importantly, the high spin filtering efficiency and the large tunneling magnetoresistance ratios are maintained throughout the entire bias voltage range. The large tunneling magnetoresistance effect is attributed to the absence of electron states in both spin-conducting channels near the Fermi level in the antiparallel magnetic configuration. Subsequently, we classify the six distinct magnetic and electric combinations of the magnetic tunnel junctions into four distinguishable storage states. Multilevel data storage is thereby achieved through the cooperative control of magnetic and electrical switching. We demonstrate that the VSi<sub>2</sub>N<sub>4</sub>/MoSiGeN<sub>4</sub>/VSi<sub>2</sub>N<sub>4</sub> and VSi<sub>2</sub>N<sub>4</sub>/bilayer-MoSiGeN<sub>4</sub>/VSi<sub>2</sub>N<sub>4</sub> van der Waals magnetic tunnel junctions are promising candidates for next-generation spintronic devices.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 47-56"},"PeriodicalIF":4.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975515","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 : 2026-01-06DOI: 10.1016/j.cjph.2025.12.039
Ya-Qin Lin , Yue-Han Lin , Rong-Can Yang , Hong-Yu Liu
Magnonics-based hybrid quantum systems have emerged as a critical platform for investigating diverse quantum correlation phenomena. In this paper, we propose a cavity-magnon optomechanical hybrid system integrated with a coherent feedback loop to enhance quantum correlations. Unlike previous schemes, GHz-band magnon and MHz-band mechanical modes in our proposal are not directly coupled, enabling the easier independent quantum control over subsystems. Moreover, the theoretical analysis and numerical simulations illustrate that the introduced feedback loop can not only significantly amplify quantum correlations but also enhance thermal stability relative to conventional configurations. Such enhancement of quantum correlations may pave the way for advancements in quantum precision measurement and quantum communication technologies.
{"title":"Quantum-correlation enhancement in cavity-magnon optomechanical hybrid systems mediated by a coherent feedback loop","authors":"Ya-Qin Lin , Yue-Han Lin , Rong-Can Yang , Hong-Yu Liu","doi":"10.1016/j.cjph.2025.12.039","DOIUrl":"10.1016/j.cjph.2025.12.039","url":null,"abstract":"<div><div>Magnonics-based hybrid quantum systems have emerged as a critical platform for investigating diverse quantum correlation phenomena. In this paper, we propose a cavity-magnon optomechanical hybrid system integrated with a coherent feedback loop to enhance quantum correlations. Unlike previous schemes, GHz-band magnon and MHz-band mechanical modes in our proposal are not directly coupled, enabling the easier independent quantum control over subsystems. Moreover, the theoretical analysis and numerical simulations illustrate that the introduced feedback loop can not only significantly amplify quantum correlations but also enhance thermal stability relative to conventional configurations. Such enhancement of quantum correlations may pave the way for advancements in quantum precision measurement and quantum communication technologies.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 39-46"},"PeriodicalIF":4.6,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975510","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 thermosolutal convection in an inclined porous medium using a local thermal non-equilibrium (LTNE) model with chemical reaction is investigated, which has valuable applications in geophysical and industrial sectors, particularly in subsurface energy extraction and chemical processing. Linear and nonlinear analyses are employed to study the stability of the system. Linear instability is examined through the normal mode, nonlinear stability is analyzed using the energy method by constructing a generalized energy functional. The bvp4c routine in MATLAB R2023a is used to solve the eigenvalue problem. The study evaluates the effect of non-dimensional parameters, including the porosity-modified conductivity ratio (τ), the Damkohler number (Dm), the inter-phase heat transfer parameter (H), the Lewis number (Le), and the solutal Rayleigh number (Rs). The results from this study show that, increasing the inclination angle, Le, and H, increases the critical thermal Rayleigh number, enhancing system stability. On the other hand, the Damkohler number destabilizes the fluid flow. A noteworthy observation is that the suppression of transverse roll structure is governed by the magnitude of the Le. Additionally, while the increase in Le and Rs, the critical Rayleigh value increases in the linear case but decreases in the nonlinear case, which causes the subcritical region to expand.
{"title":"Global stability analysis of double-diffusive convection in an inclined porous layer with chemical reaction using a thermal non-equilibrium model","authors":"Bhagya Mathapati , Ravi Ragoju , Dhananjay Yadav , Kuppalapalle Vajravelu","doi":"10.1016/j.cjph.2026.01.002","DOIUrl":"10.1016/j.cjph.2026.01.002","url":null,"abstract":"<div><div>The thermosolutal convection in an inclined porous medium using a local thermal non-equilibrium (LTNE) model with chemical reaction is investigated, which has valuable applications in geophysical and industrial sectors, particularly in subsurface energy extraction and chemical processing. Linear and nonlinear analyses are employed to study the stability of the system. Linear instability is examined through the normal mode, nonlinear stability is analyzed using the energy method by constructing a generalized energy functional. The bvp4c routine in MATLAB R2023a is used to solve the eigenvalue problem. The study evaluates the effect of non-dimensional parameters, including the porosity-modified conductivity ratio (<em>τ</em>), the Damkohler number (<em>Dm</em>), the inter-phase heat transfer parameter (<em>H</em>), the Lewis number (<em>Le</em>), and the solutal Rayleigh number (<em>Rs</em>). The results from this study show that, increasing the inclination angle, <em>Le</em>, and <em>H</em>, increases the critical thermal Rayleigh number, enhancing system stability. On the other hand, the Damkohler number destabilizes the fluid flow. A noteworthy observation is that the suppression of transverse roll structure is governed by the magnitude of the <em>Le</em>. Additionally, while the increase in <em>Le</em> and <em>Rs</em>, the critical Rayleigh value increases in the linear case but decreases in the nonlinear case, which causes the subcritical region to expand.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 10-22"},"PeriodicalIF":4.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975511","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 : 2026-01-02DOI: 10.1016/j.cjph.2026.01.001
Sy-Hann Chen , Yi-Ching Wang , Xiang-Ren He , Hsing-Chih Liang , Hai-Pang Chiang
We present a comparative investigation of plasmon-enhanced photoluminescence (PL) and surface-enhanced Raman scattering (SERS) in gold and silver nanohole arrays (AuNA and AgNA) integrated within a metal–insulator–metal (MIM) configuration and further decorated with silver nanoparticles (AgNPs). The MIM architecture, composed of an Ag buffer layer, a SiO2 spacer, and a top Au or Ag nanohole film, supports strong vertical coupling of plasmonic modes confined within the dielectric gap, enabling efficient field localization and exciton–plasmon interaction. The nanostructures were fabricated via colloidal lithography and validated by finite-element simulations. AgNA exhibited stronger near-field confinement, yielding the highest absolute PL enhancement (4.93 × over glass) and pronounced SERS response of rhodamine 6G (R6G). In contrast, AuNA showed weaker absolute signals but achieved a larger relative PL gain (1.96 vs. 1.59 for AgNA) after AgNP growth, attributed to hybridization-induced redshifts improving spectral overlap with the 4-(Dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) emission. Time-resolved PL measurements revealed shortened fluorophore lifetimes for both arrays, which were further reduced by AgNP decoration, confirming enhanced radiative decay through MIM-assisted plasmon–exciton coupling. These findings elucidate the complementary roles of material damping and MIM hybridization in tuning resonance behavior and provide design insights for plasmonic and optoelectronic applications.
我们提出了一个比较研究等离子体增强光致发光（PL）和表面增强拉曼散射（SERS）的金和银纳米孔阵列（AuNA和AgNA）集成在金属-绝缘体-金属（MIM）结构中，并进一步装饰银纳米粒子（AgNPs）。MIM结构由Ag缓冲层、SiO2间隔层和顶部Au或Ag纳米孔膜组成，支持被限制在介电间隙内的等离子体模式的强垂直耦合，实现高效的场定位和激子-等离子体相互作用。采用胶体光刻技术制备了纳米结构，并进行了有限元模拟验证。AgNA表现出更强的近场约束，产生最高的绝对PL增强（比玻璃高4.93倍）和明显的罗丹明6G （R6G）的SERS响应。相比之下，AuNA表现出较弱的绝对信号，但在AgNP生长后获得了较大的相对PL增益（1.96 vs. AgNA为1.59），这是由于杂交诱导的红移改善了与4-（二氰乙烯）-2-t-丁基-6-（1,1,7,7-四甲基朱酰基-9-烯基）- 4h -吡喃（DCJTB）发射的光谱重叠。时间分辨PL测量显示，两种阵列的荧光团寿命都缩短了，AgNP修饰进一步缩短了荧光团寿命，证实了mim辅助等离子体-激子耦合增强了辐射衰减。这些发现阐明了材料阻尼和MIM杂化在调谐共振行为中的互补作用，并为等离子体和光电子应用提供了设计见解。
{"title":"Plasmon-enhanced photoluminescence and SERS in Ag- and Au-based nanohole arrays with Ag nanoparticle decoration","authors":"Sy-Hann Chen , Yi-Ching Wang , Xiang-Ren He , Hsing-Chih Liang , Hai-Pang Chiang","doi":"10.1016/j.cjph.2026.01.001","DOIUrl":"10.1016/j.cjph.2026.01.001","url":null,"abstract":"<div><div>We present a comparative investigation of plasmon-enhanced photoluminescence (PL) and surface-enhanced Raman scattering (SERS) in gold and silver nanohole arrays (AuNA and AgNA) integrated within a metal–insulator–metal (MIM) configuration and further decorated with silver nanoparticles (AgNPs). The MIM architecture, composed of an Ag buffer layer, a SiO<sub>2</sub> spacer, and a top Au or Ag nanohole film, supports strong vertical coupling of plasmonic modes confined within the dielectric gap, enabling efficient field localization and exciton–plasmon interaction. The nanostructures were fabricated via colloidal lithography and validated by finite-element simulations. AgNA exhibited stronger near-field confinement, yielding the highest absolute PL enhancement (4.93 × over glass) and pronounced SERS response of rhodamine 6G (R6G). In contrast, AuNA showed weaker absolute signals but achieved a larger relative PL gain (1.96 vs. 1.59 for AgNA) after AgNP growth, attributed to hybridization-induced redshifts improving spectral overlap with the 4-(Dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) emission. Time-resolved PL measurements revealed shortened fluorophore lifetimes for both arrays, which were further reduced by AgNP decoration, confirming enhanced radiative decay through MIM-assisted plasmon–exciton coupling. These findings elucidate the complementary roles of material damping and MIM hybridization in tuning resonance behavior and provide design insights for plasmonic and optoelectronic applications.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 1-9"},"PeriodicalIF":4.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941397","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}
We perform a full three-dimensional particle-in-cell (3D-PIC) simulation to investigate a phase-matching scheme of ion-based high-order harmonic generation (HHG). A high-intensity laser pulse ( ∼ 1016 W/cm2, 405-nm wavelength, 50-fs pulse duration) is employed to produce He ions as the interacting medium for extending the cutoff photon energy to the water-window X-ray spectral region. The simulation result shows that phase matching for the 179th harmonic (2.26nm) is achieved by compensating the positive dipole phase with negative plasma and geometric phase shifts through laser divergence control. The relative conversion efficiency can be higher than 91% of the value with the ideal phase-matching condition.
{"title":"Full three-dimensional particle-In-Cell simulation for phase-matched ion-based high-order harmonic generation in water-window X-ray","authors":"Ying-Shan Chen , Hsu-Hsin Chu , Shih-Hung Chen , Yao-Li Liu","doi":"10.1016/j.cjph.2025.12.033","DOIUrl":"10.1016/j.cjph.2025.12.033","url":null,"abstract":"<div><div>We perform a full three-dimensional particle-in-cell (3D-PIC) simulation to investigate a phase-matching scheme of ion-based high-order harmonic generation (HHG). A high-intensity laser pulse ( ∼ 10<sup>16</sup> W/cm<sup>2</sup>, 405-nm wavelength, 50-fs pulse duration) is employed to produce He<span><math><msup><mrow></mrow><mrow><mn>1</mn><mo>+</mo></mrow></msup></math></span> ions as the interacting medium for extending the cutoff photon energy to the water-window X-ray spectral region. The simulation result shows that phase matching for the 179<sup>th</sup> harmonic (2.26nm) is achieved by compensating the positive dipole phase with negative plasma and geometric phase shifts through laser divergence control. The relative conversion efficiency can be higher than 91% of the value with the ideal phase-matching condition.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 588-599"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145920904","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 : 2026-01-01DOI: 10.1016/j.cjph.2025.12.035
Eduardo Saavedra , Ulises J. Guevara , Carlos Saji , Tamara González-Vega , Pablo Díaz , Laura M. Pérez
We investigate the spin-wave dynamics in concentric magnetic nanotori through micromagnetic simulations under perpendicular pulsed magnetic fields, using the free software MuMax3. These 3D nanostructures can host homochiral and heterochiral vortex configurations, whose spin-wave spectra strongly depend on the magnetostatic coupling parameter δ. In homochiral systems, resonance modes converge as δ increases, while in heterochiral systems, they diverge. Two distinct modes are identified: one associated with the outer surfaces of the tori and another with the inner torus. A central result is the demonstration of reversible transitions between homochiral and heterochiral vortex states using oscillating magnetic fields. The switching behavior and resonance properties vary with the coupling parameter δ, revealing the system’s dynamic versatility. This tunable chirality control positions concentric nanotori as promising candidates for future spintronic devices, enabling new opportunities for magnonic logic, non-volatile memory, and neuromorphic architectures. This work enhances the integration of 3D magnetic geometries with dynamic control, paving the way for applications in topological information processing and reconfigurable magnetic computing.
{"title":"Tunable spin-wave resonance and chirality control in concentric nanotori for advanced spintronic applications","authors":"Eduardo Saavedra , Ulises J. Guevara , Carlos Saji , Tamara González-Vega , Pablo Díaz , Laura M. Pérez","doi":"10.1016/j.cjph.2025.12.035","DOIUrl":"10.1016/j.cjph.2025.12.035","url":null,"abstract":"<div><div>We investigate the spin-wave dynamics in concentric magnetic nanotori through micromagnetic simulations under perpendicular pulsed magnetic fields, using the free software MuMax3. These 3D nanostructures can host homochiral and heterochiral vortex configurations, whose spin-wave spectra strongly depend on the magnetostatic coupling parameter <em>δ</em>. In homochiral systems, resonance modes converge as <em>δ</em> increases, while in heterochiral systems, they diverge. Two distinct modes are identified: one associated with the outer surfaces of the tori and another with the inner torus. A central result is the demonstration of reversible transitions between homochiral and heterochiral vortex states using oscillating magnetic fields. The switching behavior and resonance properties vary with the coupling parameter <em>δ</em>, revealing the system’s dynamic versatility. This tunable chirality control positions concentric nanotori as promising candidates for future spintronic devices, enabling new opportunities for magnonic logic, non-volatile memory, and neuromorphic architectures. This work enhances the integration of 3D magnetic geometries with dynamic control, paving the way for applications in topological information processing and reconfigurable magnetic computing.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 95-102"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035643","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}
In this study we obtain interior solutions and investigate structural properties of isotropic compact stars in the framework of four-dimensional regularized Einstein-Gauss-Bonnet (4DEGB) gravity. For stellar matter content, we adopt a widely used quark-matter model that approximates a realistic equation of state (EoS). By numerically integrating the modified Tolman-Oppenheimer-Volkoff equations, we obtain interior solutions for static, spherically symmetric fluid spheres. The resulting sequences are compared directly with the predictions of General Relativity (GR). Our analysis focuses on three diagnostic indicators: (i) the mass-radius profiles under GR and three representative choices of the Gauss-Bonnet coupling; (ii) the stellar compactness factor, C ≡ M/R; and (iii) the relation between stellar mass and central energy density. Recent observational studies suggest that the maximum masses inferred from the mass-radius relation may be larger than previously expected. To address this, we include a comparative set of constraints from multi-messenger astrophysical observations, including gravitational-wave event GW190814, as well as X-ray measurements from NICER for PSR J0740+6620 and PSR J0030+0451. These data provide stringent, astrophysically grounded tests of the viability of the models discussed here. Our results indicate that compact stars within 4DEGB gravity are systematically less compact and achieve moderately higher maximum masses compared to the GR case. This trend is consistent with recent theoretical analyses of compact stars in higher-curvature gravity theories and with constraints from multi-messenger astrophysics. Together, these findings suggest that regularized Gauss-Bonnet corrections constitute a plausible extension of GR in the strong-field regime.
本文在四维正则einstein - gas - bonnet （4DEGB）引力框架下，研究了各向同性致密星的内部解和结构性质。对于恒星物质含量，我们采用了一种广泛使用的夸克-物质模型，该模型近似于现实的状态方程（EoS）。通过对修正的Tolman-Oppenheimer-Volkoff方程进行数值积分，得到了静力球对称流体球的内部解。结果序列直接与广义相对论（GR）的预测进行比较。本文重点分析了三个诊断指标：(1)GR下的质量半径分布和高斯-邦纳耦合的三种代表性选择；（ii）恒星紧凑系数C ≡ M/R；(3)恒星质量与中心能量密度的关系。最近的观测研究表明，从质量-半径关系推断出的最大质量可能比先前预期的要大。为了解决这个问题，我们包括了一组来自多信使天体物理观测的比较约束，包括引力波事件GW190814，以及NICER对PSR J0740+6620和PSR J0030+0451的x射线测量。这些数据为这里讨论的模型的可行性提供了严格的、基于天体物理学的检验。我们的研究结果表明，与GR情况相比，重力在4DEGB以内的致密恒星系统上更不致密，最大质量也更高。这一趋势与最近在高曲率引力理论中对致密恒星的理论分析以及多信使天体物理学的约束是一致的。总之，这些发现表明，正则化高斯-博内修正构成了强场状态下广义相对论的合理扩展。
{"title":"Stellar modeling within regularized 4D Einstein-Gauss-Bonnet gravity in light of current astrophysical constraints","authors":"Grigorios Panotopoulos , Ángel Rincón , Ilidio Lopes","doi":"10.1016/j.cjph.2025.12.037","DOIUrl":"10.1016/j.cjph.2025.12.037","url":null,"abstract":"<div><div>In this study we obtain interior solutions and investigate structural properties of isotropic compact stars in the framework of four-dimensional regularized Einstein-Gauss-Bonnet (4DEGB) gravity. For stellar matter content, we adopt a widely used quark-matter model that approximates a realistic equation of state (EoS). By numerically integrating the modified Tolman-Oppenheimer-Volkoff equations, we obtain interior solutions for static, spherically symmetric fluid spheres. The resulting sequences are compared directly with the predictions of General Relativity (GR). Our analysis focuses on three diagnostic indicators: (i) the mass-radius profiles under GR and three representative choices of the Gauss-Bonnet coupling; (ii) the stellar compactness factor, <em>C</em> ≡ <em>M</em>/<em>R</em>; and (iii) the relation between stellar mass and central energy density. Recent observational studies suggest that the maximum masses inferred from the mass-radius relation may be larger than previously expected. To address this, we include a comparative set of constraints from multi-messenger astrophysical observations, including gravitational-wave event GW190814, as well as X-ray measurements from NICER for PSR J0740+6620 and PSR J0030+0451. These data provide stringent, astrophysically grounded tests of the viability of the models discussed here. Our results indicate that compact stars within 4DEGB gravity are systematically less compact and achieve moderately higher maximum masses compared to the GR case. This trend is consistent with recent theoretical analyses of compact stars in higher-curvature gravity theories and with constraints from multi-messenger astrophysics. Together, these findings suggest that regularized Gauss-Bonnet corrections constitute a plausible extension of GR in the strong-field regime.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 57-66"},"PeriodicalIF":4.6,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035646","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 : 2025-12-31DOI: 10.1016/j.cjph.2025.12.008
C. Dang-Ra , A.C. Chamgoué , A. Troisi , G. Filatrella , R. Yamapi
The sensitivity of self-sustaining biological systems to external influences and the reaction environment has promted analytical and numerical analysis of the bifurcation of the birhythmic parameters of the self-sustaining system. Considering the influence of magnetic flux, analytically, the self-feedback method is applied to control the birhythmic zone of the solution map. As the intensity of the control coefficient increases, the birhythmic zone tends to disappear. The non-monotonic behavior and chaotic state observed on the stochastic bifurcation via the Fokker-Planck-Kolmogorov equation and the Lyapunov exponent are influenced by the magnetic flux. Gaussian white noise introduces an additional phenomenon of unpredictability into the system, causing it to enter various dynamic regimes, its combination with magnetic flux accentuates the control of the system’s parameters.
{"title":"Control of birhythmicity, and stochastic bifurcation in a self-sustaining system coupled to magnetic flux and driven by noise","authors":"C. Dang-Ra , A.C. Chamgoué , A. Troisi , G. Filatrella , R. Yamapi","doi":"10.1016/j.cjph.2025.12.008","DOIUrl":"10.1016/j.cjph.2025.12.008","url":null,"abstract":"<div><div>The sensitivity of self-sustaining biological systems to external influences and the reaction environment has promted analytical and numerical analysis of the bifurcation of the birhythmic parameters of the self-sustaining system. Considering the influence of magnetic flux, analytically, the self-feedback method is applied to control the birhythmic zone of the solution map. As the intensity of the control coefficient increases, the birhythmic zone tends to disappear. The non-monotonic behavior and chaotic state observed on the stochastic bifurcation via the <em>Fokker-Planck-Kolmogorov</em> equation and the Lyapunov exponent are influenced by the magnetic flux. Gaussian white noise introduces an additional phenomenon of unpredictability into the system, causing it to enter various dynamic regimes, its combination with magnetic flux accentuates the control of the system’s parameters.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 193-207"},"PeriodicalIF":4.6,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074731","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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