Chinese Journal of Physics最新文献

{"title":"Meta-optics empowered by all-silicon quarter-wave plates for generating focused vortex beams","authors":"Hui Li ,&nbsp;Jie Li ,&nbsp;Chenhui Zhao ,&nbsp;Chenglong Zheng ,&nbsp;Hang Xu ,&nbsp;Wenhui Xu ,&nbsp;Qi Tan ,&nbsp;Chunyu Song ,&nbsp;Yun Shen ,&nbsp;Jianquan Yao","doi":"10.1016/j.cjph.2024.10.005","DOIUrl":"10.1016/j.cjph.2024.10.005","url":null,"abstract":"<div><div>The Poynting vector associated with the focused vortex beam (FVB) that carries orbital angular momentum (OAM) is oriented in a twisted manner relative to the principal axis of propagation. This characteristic has significant applications in advanced fields, including high-dimensional information processing, high-resolution imaging, and particle manipulation. Currently, complex optical systems that operate on alignment principles for generating FVBs have been miniaturized by metasurfaces, resulting in the achievement of polarization-dependent vectorized behavior. Nevertheless, generating and manipulating FVBs that carry OAM in the terahertz (THz) range remains a significant challenge. This difficulty arises particularly when utilizing quarter-wave plates (QWPs) that serve both polarization conversion and polarization filtering functions. Here, we experimentally demonstrate a planar all-dielectric array capable of generating FVBs with high power density within a single-handed circularly polarized channel. Engineered QWP meta-atoms are utilized as candidates for the efficient generation of the desired FVB through the application of dynamic phase gradients. A series of samples were fabricated to assess the effectiveness of this design strategy in converting an incident linearly polarized THz beam into arbitrary single-handed circularly polarized FVBs. Leveraging the high degree of freedom inherent in polarization multiplexing coding, the proposed QWP metasurface can generate FVBs exhibiting topological charge evolution along the longitudinal direction. This capability further underscores its robust polarization modulation proficiency. This work presents a generalized framework for the polarization-dependent generation of ultracompact structural optical fields, which may have potential applications in highly integrated THz communication systems.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417948","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":"Conserved mutual information for discrete and continuous variables in dilaton black hole","authors":"Shu-Min Wu ,&nbsp;Xiao-Wei Teng ,&nbsp;Hao-Yu Wu ,&nbsp;Jin-Xuan Li ,&nbsp;Xiao-Li Huang ,&nbsp;Rui Bao","doi":"10.1016/j.cjph.2024.09.039","DOIUrl":"10.1016/j.cjph.2024.09.039","url":null,"abstract":"<div><div>The information paradox of black holes has always been a hot topic at the forefront of theoretical physics. In this paper, we aim to understand the information paradox of the dilaton black hole from the perspective of the total correlation quantified by mutual information between the initial subsystems <span><math><mi>A</mi></math></span> and <span><math><mi>B</mi></math></span>. We find that the dilaton gravity can redistribute initial mutual information for discrete and continuous variables between the subsystems <span><math><mi>A</mi></math></span> and <span><math><mi>B</mi></math></span>, but cannot redistribute initial entanglement. Interestingly, the sum of physically accessible and inaccessible mutual information is equal to the initial mutual information. Therefore, physically accessible mutual information is transformed into physically inaccessible mutual information by the dilaton gravity of the black hole. From the perspective of mutual information, the information of black holes is conserved and not lost.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445598","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":"Quantum improved regular Kerr black holes","authors":"Chiang-Mei Chen ,&nbsp;Yi Chen ,&nbsp;Akihiro Ishibashi ,&nbsp;Nobuyoshi Ohta","doi":"10.1016/j.cjph.2024.10.001","DOIUrl":"10.1016/j.cjph.2024.10.001","url":null,"abstract":"<div><div>We study the quantum improvement of Kerr black holes with mass-dependent scale identifications in asymptotically safe gravity. We find that a physically sensible identification can only be a function of <span><math><mrow><mi>M</mi><mi>r</mi></mrow></math></span> and the area <span><math><mrow><mi>A</mi><mo>=</mo><mn>4</mn><mi>π</mi><mrow><mo>(</mo><msup><mrow><mi>r</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msup><mrow><mi>a</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span> where <span><math><mi>M</mi></math></span> is the mass of the black hole and <span><math><mi>a</mi></math></span> is an angular momentum parameter. We then discuss various properties of the rotating quantum black holes for a simple choice of the identification. We show that the resulting regular rotating black holes have the following nice properties: (i) admitting a consistent black hole thermodynamics at the horizon, (ii) resolving the ring singularity, (iii) partially eliminating closed time-like curves present in the classical Kerr black holes.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445599","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":"Impact of flexible walls of curved channel on biological flow of Reiner–Rivlin fluid","authors":"S. Hina","doi":"10.1016/j.cjph.2024.09.045","DOIUrl":"10.1016/j.cjph.2024.09.045","url":null,"abstract":"<div><div>In this study, the Reiner–Rivlin fluid model is opted for examination as the complex dynamical fluid and is flowing on account of the waves travelling on the walls of flexible curved channel. The governing equations are solved analytically up to the first order to analyse the velocity profiles. As the governing equation is highly nonlinear, so the problem is solved by regular perturbation technique about small wave number. After the implication of regular perturbation, the second order Cauchy Euler ordinary differential equations are obtained for both the systems. A detailed analysis is conducted on the effects of diverse factors, such as the rheological properties of fluid, the curvature radius of the channel, the wave amplitude and the wall properties. The velocity of the fluid enhanced by increasing wall properties parameters, wave number, Reynolds number and the amplitude ratio parameter. It is also observed that the Reiner–Rivlin fluid flows slowly as compare to the Newtonian fluid, this type of findings can be helpful for the understanding of many physiological processes, like blood flow and food swallowing. This study enlightens the interaction between the curved nature of the channel and Reiner–Rivlin fluid flow in peristalsis that can be a great contribution for the designing of biomedical devices. Such types of problems have great significance in many physiological processes and engineering applications like microfluidic devices and drug delivery systems.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526144","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":"Flux dynamics, anisotropy in Jc and vortex phase diagram of H+-intercalated FeSe single crystal","authors":"Zhiwei Wen ,&nbsp;Tao Jia ,&nbsp;Yusen Xiao ,&nbsp;Yuxian Wu ,&nbsp;Yong Li ,&nbsp;Shulong Li ,&nbsp;Yajing Cui ,&nbsp;Ruidan Zhong ,&nbsp;Yongliang Chen ,&nbsp;Cuihua Cheng ,&nbsp;Yong Zhao","doi":"10.1016/j.cjph.2024.09.042","DOIUrl":"10.1016/j.cjph.2024.09.042","url":null,"abstract":"<div><div>This paper investigates the superconductivity, pinning, and vortex dynamics of FeSe before and after protonation. The study shows that, after being protonated, FeSe's superconducting critical temperature <em>T</em>_c has been increased to more than 40 K and the critical current density <em>J</em>_c has also been increased from 2.1 × 10⁴ A/cm² to 1.2 × 10⁶ A/cm², with significantly larger magnetic relaxation rates (<em>Q</em>). Meanwhile, the critical current density anisotropy (<em>γ</em>) decreases substantially while the upper critical field <em>H</em>_c2 increases from 13 T to 91 T after protonation. In addition, the reasons for the absence of the second peak effect in H<em>_x</em>-FeSe were explored. This investigation also reveals the existence of the vortex phase transition associated with the pinning behavior in protonated FeSe, demonstrated by the foot-like characteristics of resistivity. Based on these results, the vortex phase diagrams of FeSe before and after protonation were established. These findings provide important insights for exploring new high-temperature superconductors and their magnetic flux dynamics through protonation.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441578","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":"Entanglement, quantum steering, and Bell nonlocality in the Tavis–Cummings system","authors":"Biao-Liang Ye","doi":"10.1016/j.cjph.2024.09.040","DOIUrl":"10.1016/j.cjph.2024.09.040","url":null,"abstract":"<div><div>In this work, we focus on quantum correlations, specifically entanglement, quantum steering, and Bell nonlocality within the Tavis–Cummings model. This study investigates these quantum correlations in the context of various fields existing in the cavity. The findings reveal the hierarchy of quantum correlations—entanglement, quantum steering, and Bell nonlocality—in two two-level atoms under the influence of thermal, coherent, and squeezed vacuum states. The dynamic process demonstrates certain oscillations, with particular emphasis on the presence of asymmetric quantum steering.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417945","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":"Citation analysis on publications from Academia Sinica","authors":"Ding-wei Huang","doi":"10.1016/j.cjph.2024.09.037","DOIUrl":"10.1016/j.cjph.2024.09.037","url":null,"abstract":"<div><div>This study employs the Web of Science to examine patterns and trends in Academia Sinica’s scholarly publications, aiming to offer insights into both the quantity and quality of its research output. Initial findings reveal trends such as saturation in paper counts, increase in citation counts, diversification of journals, shifts in prominent research areas, widening disciplinary variances, and an evolving landscape of collaborations. Although the study does not differentiate among Academia Sinica’s three divisions, specific results related to the Institute of Physics will be addressed. Additionally, comparisons with other research institutes will be explored.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417955","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":"Study on highly selective NO2 gas sensors based on (Fe, Mo)-doped monolayer WSe2","authors":"Li Ye,&nbsp;Yongchao Liang","doi":"10.1016/j.cjph.2024.09.044","DOIUrl":"10.1016/j.cjph.2024.09.044","url":null,"abstract":"<div><div>The two-dimensional (2D) material WSe₂ is frequently employed in gas sensors due to its excellent electrical properties. However, the weak interaction between the pristine WSe₂ and gas molecules limits its application. Therefore, in this paper, the adsorption behavior of transition metal X (X = Fe, Mo) atom-doped monolayers WSe₂ on H and O atoms and molecules of NO₂, HCN, and CO gases is investigated to gain insights into the physical mechanisms of adsorbent-substrate interactions. Doping significantly improves the adsorption properties between the substrate and the gas molecules, with the best adsorption showing for NO₂ gas molecules and O atoms. The relationship between transition metals and the improvement of adsorption performance is explored by the center position of transition metal d orbitals in different systems, and it is found that the higher the center position of the transition metal d band, the stronger the adsorption between adsorbent and substrate. Compared to pristine WSe₂, Mo atom doping in the transition metal doped system has higher adsorption sensitivity to gas molecules and exhibits highly selective adsorption and chemisorption behaviors through high adsorption energies and electron transfer to NO₂ molecules. It is demonstrated that X (X = Fe, Mo) doped WSe₂ can be used as a gas-sensitive material for efficient gas detection.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417823","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":"Magnetic and thermodynamic properties of mixed spin-3/2 and spin-3 Ising ferrimagnets on a 2D triangular lattice: Monte Carlo study","authors":"D. Fouejio,&nbsp;P. Noudem,&nbsp;S.S. Zekeng","doi":"10.1016/j.cjph.2024.09.041","DOIUrl":"10.1016/j.cjph.2024.09.041","url":null,"abstract":"<div><div>Monte Carlo methods in the presence and absence of an external magnetic field were used to investigate the thermodynamic and magnetic properties of the mixed spins (3/2, 3) Ising ferrimagnets in a 2D triangular lattice consisting of sublattices A, B, and C. Two types of mixing were considered: <span><math><mrow><mover><mi>S</mi><mo>→</mo></mover><mo>=</mo><mrow><mo>(</mo><mrow><msub><mi>S</mi><mi>A</mi></msub><mo>,</mo><mspace></mspace><msub><mi>S</mi><mi>B</mi></msub><mo>,</mo><mspace></mspace><msub><mi>S</mi><mi>C</mi></msub></mrow><mo>)</mo></mrow><mo>=</mo><mrow><mo>(</mo><mrow><mn>3</mn><mo>/</mo><mn>2</mn><mo>,</mo><mspace></mspace><mn>3</mn><mo>,</mo><mspace></mspace><mn>3</mn></mrow><mo>)</mo></mrow></mrow></math></span> (Model I) and <span><math><mrow><mover><mi>S</mi><mo>→</mo></mover><mo>=</mo><mrow><mo>(</mo><mrow><msub><mi>S</mi><mi>A</mi></msub><mo>,</mo><mspace></mspace><msub><mi>S</mi><mi>B</mi></msub><mo>,</mo><mspace></mspace><msub><mi>S</mi><mi>C</mi></msub></mrow><mo>)</mo></mrow><mo>=</mo><mrow><mo>(</mo><mrow><mn>3</mn><mo>/</mo><mn>2</mn><mo>,</mo><mspace></mspace><mn>3</mn><mo>,</mo><mspace></mspace><mn>3</mn><mo>/</mo><mn>2</mn></mrow><mo>)</mo></mrow></mrow></math></span> (Model II). In contrast to bipartite lattices, the antiferromagnetic coupling between spin-3/2 and spin-3 in the triangular lattice leads to geometric frustrations that impact magnetic properties. Determination of ground state phase diagrams, combined with verification of whether or not there was magnetic hysteresis when crossing each transition line, revealed first- and second-order phase transition lines, as well as multicritical points. The temperature investigation in the absence of an external magnetic field revealed rich magnetic properties such as 1st- and 2nd-order phase transitions, N- and L-type compensation points, tricritical points, and critical endpoints, as well as M-, P-, Q-, R- and S-type total magnetization behaviours. The effect of the crystal field on finite-temperature phase diagrams and compensation behaviour was also carried out. As a result, the critical temperatures of Model II become constant when the crystal field is sufficiently strong. In contrast, several critical values of the crystal field for which the critical temperature is zero were identified for Model I. In the presence of a magnetic field, hysteresis behaviour and associated magnetic properties such as coercivity and magnetic remanence were investigated. The effect of crystal field and temperature was explored. Hysteresis of one to four loops were found at low temperatures when the crystal field varied. Finally, as the temperature rises, the hysteresis loops' area decreases to zero at high temperatures.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526150","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":"Nonlinear dynamics of micropolar two-phase fluids: Multiple exact solutions","authors":"Waqar Khan Usafzai ,&nbsp;Emad H. Aly ,&nbsp;Ioan Pop","doi":"10.1016/j.cjph.2024.09.034","DOIUrl":"10.1016/j.cjph.2024.09.034","url":null,"abstract":"<div><div>Dual and triple solutions induced by a flexible planar surface for a micropolar two-phase fluid model are studied. The two-phase behavior in the micropolar fluid model occurs due to phase transitions between the fluid phases, influenced by interfacial stresses and heat transfer. The physical implications of these transitions are significant in understanding flow behavior under different mechanical and thermal conditions. This study examines the critical parameters and conditions that lead to these phase transitions, resulting in dual or triple solutions in the flow dynamics. The flow and thermal fields are exact solutions of the steady, two-dimensional two-phase micropolar fluid equations in the form of similarity solution. It is shown that dual and triple exact solutions exist for a highly nonlinear system. Triple solutions exist for the skin friction and temperature gradient identified by the critical numbers <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> and <span><math><mrow><msub><mrow><mi>μ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>.</mo></mrow></math></span> It is noted that for sufficiently small values of stretching strength parameter the dual branches for two of the triple solutions exist only in the regions <span><math><mrow><mi>μ</mi><mo>≥</mo><msub><mrow><mi>μ</mi></mrow><mrow><msub><mrow><mi>c</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></msub><mo>,</mo></mrow></math></span> and <span><math><mrow><mi>μ</mi><mo>≤</mo><msub><mrow><mi>μ</mi></mrow><mrow><msub><mrow><mi>c</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></msub><mo>,</mo></mrow></math></span> where <span><math><mrow><msub><mrow><mi>μ</mi></mrow><mrow><msub><mrow><mi>c</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></msub><mo>=</mo><mo>−</mo><mn>5</mn><mo>.</mo><mn>23</mn></mrow></math></span> and <span><math><mrow><msub><mrow><mi>μ</mi></mrow><mrow><msub><mrow><mi>c</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></msub><mo>=</mo><mo>−</mo><mn>7</mn><mo>.</mo><mn>72</mn><mo>.</mo></mrow></math></span> Numerical results are also provided, validating the model and offering insights into its accuracy and behavior of the model.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417956","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}