Chinese Journal of Physics最新文献

{"title":"Effect of laser chirping on third harmonic generation in anharmonic clusters with ripple on cluster density","authors":"","doi":"10.1016/j.cjph.2024.09.005","DOIUrl":"10.1016/j.cjph.2024.09.005","url":null,"abstract":"<div><p>A proposed model delves into the resonant enhancement of third harmonic generation (THG) by a short-pulse laser inside nanoclustered plasma under the influence of density ripple. An intense chirped laser pulse incident on a clustered plasma of argon gas displaces the electrons of the medium and produces a restoring force. This force is considered to vary nonlinearly with electron displacement, leading to the anharmonic response of the electron clouds of the cluster. The nonlinear current at the third harmonic frequency arises from the perturbation of the electron density of the cluster by the ponderomotive force exerted on them by the incident laser pulse. Applying ripple in cluster density and electron density of surrounding plasma enables the phase-matching criteria for THG to be satisfied, which leads to enhanced harmonic output. An anharmonic structure of clusters exhibits strong optical nonlinearities, resulting in the plasmon resonance broadening and producing harmonics with greater efficiency. Numerical analysis shows that the chirp parameter of the laser pulse and ripple on cluster density enhance system nonlinearity causing the generation of a third harmonic of enhanced amplitude. The study explores how different factors such as laser intensity, cluster size, ripple parameter, chirp parameter, and electron excursion influence the efficiency of THG.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241962","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}

{"title":"Frequency chimera state induced by time delays in FitzHugh-Nagumo neural networks","authors":"","doi":"10.1016/j.cjph.2024.09.009","DOIUrl":"10.1016/j.cjph.2024.09.009","url":null,"abstract":"<div><p>The delay of information transmission is an inherent factor of the nervous systems, which has great influences on their collective dynamic behaviors. In this paper, we constructed a ring neural network using FitzHugh-Nagumo (FHN) neuron model as the network node and memristive synapses as the connection mode. Our primary focus was on investigating the effects of time delay and coupling strength on the firing frequency of neurons. Simulation results revealed that the frequency chimera state could be induced in the neural network with appropriate time delay, which is a new type of chimera state characterized by firing frequency rather than traditional membrane potential. By adjusting the time delay properly, the neural network can also display multi-cluster frequency chimera states that coexisted with various incoherent regions and coherent regions. Meanwhile, we exhibit that initial value and coupling strength could have great influences on the effects of time delay on inducing frequency chimera state of the nervous systems.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142241516","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}

{"title":"Fractional relaxation model with general memory effects and stability analysis","authors":"","doi":"10.1016/j.cjph.2024.09.006","DOIUrl":"10.1016/j.cjph.2024.09.006","url":null,"abstract":"<div><p>Voigt and Maxwell models are popularly used to model viscoelastic materials’ property. They are often presented in form of fractional relaxation equations. In order to describe rich viscoelasticity, a general Caputo derivative is introduced in fractional modeling. Then this work studies attractivity and asymptotic stability of the Caputo fractional relaxation equation with general memory effects. Firstly, the considered problem is transformed into an integral equation. A mapping and an attractive set are constructed. Furthermore, the existence of fixed points on the attractive set are investigated by using fixed point theorems. Finally, the effectiveness and convenience of the stability theory are verified through two numerical examples.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168505","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}

{"title":"Generalization and analytic exploration of soliton solutions for nonlinear evolution equations via a novel symbolic approach in fluids and nonlinear sciences","authors":"","doi":"10.1016/j.cjph.2024.09.004","DOIUrl":"10.1016/j.cjph.2024.09.004","url":null,"abstract":"<div><p>In this work, we analyze the new generalized soliton solutions for the nonlinear partial differential equations with a novel symbolic bilinear technique. The proposed approach constructs the soliton solutions depending on the arbitrary parameters, which generalizes the soliton solutions with these additional parameters. Examining phase shifts and their dependence on the parameters influences how solitons collide, merge, or pass through each other, which is essential for the nonlinear analysis of solitons. Using the proposed technique, we examine the well-known (1＋1)-dimensional Korteweg–de Vries (KdV) and (2＋1)-dimensional Kadomtsev–Petviashvili (KP) equations with a comparative analysis of soliton solutions in the Hirota technique. We construct the generalized solitons solutions for both examined equations up to the third order, providing a better understanding of formed solitons with arbitrary parameter choices. The Cole-Hopf transformations are used to construct the bilinear form in the auxiliary function using Hirota’s <span><math><mi>D</mi></math></span>-operators for both investigated KdV and KP equations It discusses the phase shift depending on parameters and compares it to the phase shift in Hirota’s soliton solutions. We utilize <em>Mathematica</em>, a computer algebra system, to obtain the generalized solitons and analyze the dynamic behavior of the obtained solutions by finding the values for the parameters and the relationships among them. Solitons are localized waves that appear in different fields of nonlinear sciences, such as oceanography, plasmas, fluid mechanics, water engineering, optical fibers, and other sciences.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168504","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}

{"title":"Thickness-dependent magnetotransport and ultrafast dynamic properties of epitaxial Bi2Se3/InP(111) thin films grown using pulsed laser deposition","authors":"","doi":"10.1016/j.cjph.2024.08.030","DOIUrl":"10.1016/j.cjph.2024.08.030","url":null,"abstract":"<div><p>Bi₂Se₃ thin films with various thicknesses of 44, 94, 190 QL (1 QL = 0.955 nm) were epitaxially grown on InP (111) substrates using a Bi₂Se₈ target and pulsed laser deposition. All the Bi₂Se₃ thin films exhibited highly <em>c</em>-axis preferred orientation and well in-plane orientation with six-fold symmetric diffraction patterns of Bi₂Se₃{015} facets. The films had a clean and smooth surface with triangular step-and-terrace pyramid features and a small average roughness <em>R_a</em> ≤ 1.47 nm. The hardness and Young's modulus of a 190 QL-thick epitaxial Bi₂Se₃ film were found to be 2.1 ± 0.1 GPa and 58.6 ± 4.1 GPa, respectively. The Bi₂Se₃ thin films exhibited the typical two-dimensional weak antilocalization magnetoresistance (2D WAL MR) in a low magnetic field regime (<em>B</em> ± 0.5T). Meanwhile, they presented a parabola-like MR behavior for 190-QL-thick film, and linear MR for the thinner films at a high <em>B</em> field regime (<em>B</em> ≥ 3 T). The MR results suggest the presence of 2D topological surface states together with a dominant bulk state in the Bi₂Se₃ films. Furthermore, we observed two gigahertz acoustic phonon modes at 24.04 ± 2.05 GHz and 48.11 ± 2.02 GHz in the Bi₂Se₃ films induced by ultrafast laser pulses.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142136528","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}

{"title":"Phase structure of quantum corrected charged AdS black hole surrounded by perfect fluid dark matter","authors":"","doi":"10.1016/j.cjph.2024.09.001","DOIUrl":"10.1016/j.cjph.2024.09.001","url":null,"abstract":"<div><p>We derive a solution of a quantum corrected charged AdS black hole surrounded by perfect fluid dark matter (PFDM). The thermodynamic quantities and the modified first law of thermodynamics are obtained by considering the black hole mass as chemical enthalpy rather than energy. A first order phase transition (small to large black holes) is recognized from the swallowtail in the Gibbs free energy <span><math><mi>G</mi></math></span> versus Hawking temperature <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span> graph. The black hole exhibits the characteristic “standard liquid/gas behavior” of van der Waals fluids on the <span><math><mrow><mi>P</mi><mo>−</mo><mi>V</mi></mrow></math></span> graph. By further studying the heat capacity of the black hole, we identify a second order phase transition at the event horizons <span><math><msub><mrow><mi>x</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>, respectively. Thus, we demonstrate that a quantum corrected charged AdS black hole surrounded by PFDM can be studied for its thermodynamic stability and phase transition from the perspective of black hole chemistry.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168393","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}

{"title":"Nanoscale photoemission in a plasmon focusing lens with a nanohole explored by time-of-flight photoemission electron microscopy","authors":"","doi":"10.1016/j.cjph.2024.08.044","DOIUrl":"10.1016/j.cjph.2024.08.044","url":null,"abstract":"<div><p>Propagating surface plasmon polaritons (SPPs) provide an important platform for the design of various photoelectric devices such as nanometer-scale ultrafast electron sources. Here, a high-brightness nanoscale photoelectron source in a plasmon focusing lens with a nanohole is investigated using time-of-flight photoemission electron microscopy (TOF-PEEM). By exploiting the high spatial resolution of TOF-PEEM, it is found that the photoemission was localized at the nanoscale in both x and y directions. In addition, a large multiphoton photoemission enhancement was achieved and a strong-field effect was observed due to the interplay between the SPP and the nanohole. This paper provides a new idea for the development of the high-brightness nanoscale photoelectron sources and a deep understanding of the interplay between SPP and LSP.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229218","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}

{"title":"Spectroscopic study of exotic fully-heavy tetraquark states QQQ̄Q̄ (Q∈{c,b})","authors":"","doi":"10.1016/j.cjph.2024.08.040","DOIUrl":"10.1016/j.cjph.2024.08.040","url":null,"abstract":"<div><p>In this article, we utilize the non-relativistic potential model to investigate the mass spectra of exotic fully-heavy tetraquark states <span><math><mrow><mi>Q</mi><mi>Q</mi><mover><mrow><mi>Q</mi></mrow><mrow><mo>̄</mo></mrow></mover><mover><mrow><mi>Q</mi></mrow><mrow><mo>̄</mo></mrow></mover></mrow></math></span> (<span><math><mrow><mi>Q</mi><mo>∈</mo><mrow><mo>{</mo><mi>c</mi><mo>,</mo><mi>b</mi><mo>}</mo></mrow></mrow></math></span>), specifically examining <span><math><mrow><mrow><mo>[</mo><mi>c</mi><mi>c</mi><mo>]</mo></mrow><mrow><mo>[</mo><mover><mrow><mi>c</mi></mrow><mrow><mo>̄</mo></mrow></mover><mover><mrow><mi>c</mi></mrow><mrow><mo>̄</mo></mrow></mover><mo>]</mo></mrow></mrow></math></span> and <span><math><mrow><mrow><mo>[</mo><mi>b</mi><mi>b</mi><mo>]</mo></mrow><mrow><mo>[</mo><mover><mrow><mi>b</mi></mrow><mrow><mo>̄</mo></mrow></mover><mover><mrow><mi>b</mi></mrow><mrow><mo>̄</mo></mrow></mover><mo>]</mo></mrow></mrow></math></span>.We treat these states as diquark–antidiquark bound systems governed by a diquark–antidiquark color Coulomb plus confining linear potential.To determine the masses of the ground state and its radially and orbitally excited states for fully-heavy tetraquark states, we incorporate perturbative spin–spin, spin–orbit and spin–tensor interaction potentials.Our results of masses of <span><math><mrow><mi>n</mi><mi>S</mi></mrow></math></span>, <span><math><mrow><mi>n</mi><mi>P</mi></mrow></math></span> and <span><math><mrow><mi>n</mi><mi>D</mi></mrow></math></span> states of fully heavy tetraquark states are compared with both other theoretical predictions and experimental data.Remarkably, our results closely align with theoretical as well as experimental observations.Furthermore, our findings also support the assignment of <span><math><msup><mrow><mi>J</mi></mrow><mrow><mi>P</mi><mi>C</mi></mrow></msup></math></span> quantum numbers to the recently observed structures by ATLAS, LHCb and CMS collaborations, including <span><math><mrow><mi>X</mi><mrow><mo>(</mo><mn>6600</mn><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>X</mi><mrow><mo>(</mo><mn>6900</mn><mo>)</mo></mrow></mrow></math></span> and <span><math><mrow><mi>X</mi><mrow><mo>(</mo><mn>7200</mn><mo>)</mo></mrow></mrow></math></span>.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142164582","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}

{"title":"Flow and heat transfer of non-miscible micropolar and Newtonian fluid in porous channel sandwiched between parallel plates","authors":"","doi":"10.1016/j.cjph.2024.08.041","DOIUrl":"10.1016/j.cjph.2024.08.041","url":null,"abstract":"<div><p>An analytical approach has been considered to inspect the flow and heat transfer of immiscible Newtonian and micropolar fluid in a porous medium. This study aims to elucidate the Darcy effect on the model in which isotropic porous regions with different permeability are used. The model of the current problem explains that the flow region is divided into two regions: Newtonian fluid flows in the upper layer, and micropolar fluid flows in the lower layer. Different constant temperatures imposed at boundary walls, heat transfer does not affect the pressure gradient. The governing equations are solved analytically by applying a linear differential equation (LDE). The effect of associated physical parameters such as material parameter, Darcy number, Eckert number, Prandtl number, and viscosity ratio on velocity, micro-rotation, heat transfer, flow rate, heat transfer rate, wall shear stress, and Nusselt number have been inspected. The most significant finding of this research work is that increasing the Darcy number signifies enhanced permeability, resulting in a higher flow rate. The heat transfer rate at the top occurs maximum when the material parameter’s range is minimum while raising the viscosity ratio leads to an increasing heat transfer rate at the bottom. Enhancement in material parameter influences Nusselt number and decreases in nature. The findings of our study are verified with the previously established results. The present work has a setup that is useful in petroleum extraction, transport problems in reservoir rock of an oil field, improving nutrient transport and thermal regulation in tissue engineering, and designing more efficient drug delivery systems and biomedical devices.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142229220","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}

{"title":"QPOs and circular orbits around black holes in Chaplygin-like cold dark matter","authors":"","doi":"10.1016/j.cjph.2024.09.002","DOIUrl":"10.1016/j.cjph.2024.09.002","url":null,"abstract":"<div><p>Understanding the nature of dark energy in the universe is an actual issue in theoretical astrophysics and cosmology. One way to do it is by probing dark fluids with different equations of states (EoS). In the present work, we consider a Schwarzschild black hole (BH) surrounded by a dark fluid with a Chaplygin-like EoS as a generalized version of the Chaplygin EoS. We first investigate the effects of the dark fluid parameters on the horizon properties of the BH. The effective mass of the spacetime is calculated and analyzed under the dark fluid parameters. The scalar invariants of the BH spacetime are also calculated, and it is shown that the spacetime curvature increases as the dark fluid parameter increases. Next, we studied the circular motion of the test particle around the BH. As standard particle motion investigations, we analyze the effective potential of the particles for circular motion, specific energy, and angular corresponding to circular orbits with zero and nonvanishing values of the dark fluid intensity. In addition, we study the innermost stable circular orbits (ISCO). It is observed that there is an outermost stable circular orbit (OSCO) due to the presence of the dark fluid. It also shows that at a critical value of the dark fluid intensity parameter, ISCO and OSCO take the same radius. We calculate the frequency of Keplerian orbits and radial and vertical oscillations of the particles along stable circular orbits. We also applied orbital data from hotspots observed near Sgr A* to obtain upper and lower values for the EoS parameter. Finally, we investigate quasiperiodic oscillations and obtain the mass-to-EoS parameter relations for GRS J1915-105 and XTE 1550-564.</p></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142270969","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}