Indian Journal of Physics最新文献

{"title":"Energy levels, wavelengths, transition probabilities, weighted oscillator strengths, and line strengths for carbon-like ions with Z = 21–30","authors":"W. Tang, B. L. Deng, G. S. Zhang, B. Meng, R. Yang, S. Wang","doi":"10.1007/s12648-024-03324-y","DOIUrl":"https://doi.org/10.1007/s12648-024-03324-y","url":null,"abstract":"<p>In this study, the energy levels (<i>E</i>), lifetimes (<i>τ</i>), wavelengths (<i>λ</i>), transition probabilities (<i>A</i>), weighted oscillator strengths (<i>gf</i>) and line strengths (<i>S</i>) among the (1<i>s</i>²)2<i>s</i>²2<i>p</i>², 2<i>s</i>²2<i>p</i>3<i>s</i>, 2<i>s</i>²2<i>p</i>3<i>d</i>, and 2<i>s</i>2<i>p</i>²3<i>p</i> configurations of carbon-like ions with <i>Z</i> = 21–30 were determined using the multiconfiguration Dirac–Hartree–Fock (MCDHF) method. We confirmed the reliability of the energy levels by comparing them with the results of other theoretical methods and experimental observations. The present wavelengths for C-like ions were in good agreement with the previous experimental and theoretical results, with most wavelength differences below 0.8%. Based on the relative deviation (<i>dT</i>) and line strengths (<i>S</i>), respectively, we estimated the uncertainty of the computed transition data. Out of the 1300 transitions computed in this work, 1207 (699) have uncertainties fewer than or equal to 7% as determined by <i>dT</i> (<i>S</i>). We hope these data will be utilized to expand the C-like ion database and provide reference information for experimental studies in plasma experiments.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Onset of identical synchronization in the spatial evolution of optical power in a waveguide coupler","authors":"Jyoti Prasad Deka","doi":"10.1007/s12648-024-03348-4","DOIUrl":"https://doi.org/10.1007/s12648-024-03348-4","url":null,"abstract":"<p>In this work, we investigated the spatial evolution of optical power in a closed-form optical waveguide configuration consisting of six passive waveguides and each of the waveguides exhibits equal strength of Kerr nonlinearity. We considered only nearest neighbor interaction between the waveguides. We found that in the case of low Kerr nonlinearity, spatial evolution of optical power shows identical synchronization. But when we increased the strength of Kerr nonlinearity, we discovered that spatial evolution of optical power in all waveguides exhibits independent characteristics. On the other hand, we have studied the impact of the coupling constant on the synchronization dynamics of our system. Our findings showed us that strong coupling can strengthen the collective dynamics in the presence of strong Kerr nonlinearity. From our results, we can conclude that Kerr nonlinearity in our system plays the role of disorder parameter that destroys as well as alters the synchronization behavior of evolution of optical power in the waveguides and coupling constant, on the other hand, plays the role of an antagonist and restores synchronization in the model.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"A DFT approach on the investigations of the structural and optoelectronic properties of lead-free and Ge-based mixed halide perovskites RbGeBr2Cl and RbGeI2Cl","authors":"Hameed T. Abdulla","doi":"10.1007/s12648-024-03354-6","DOIUrl":"https://doi.org/10.1007/s12648-024-03354-6","url":null,"abstract":"<p>In this study, the structural, electronic and optical properties of the tetragonal-phase of the free-lead mixed halides perovskites RbGeI₂Cl and RbGeBr₂Cl are investigated. These materials have raised an interest due to their enhanced electronic and optical properties, demonstrated by high charge carrier mobility and adjustable band gap. The calculations employed ab-initio methods, predominantly based on the density functional theory (DFT), the exchange–correlation functional is processed with the generalized gradient approximation (GGA) approach which uses a ‘flavour’ of the Perdew Burke Ernzerhof (PBE). The DFT framework allows to study the structural parameters, band structure, and density of states (DOS). The calculations of the band structure show that RbGeI₂Cl and RbGeBr₂Cl have a direct band gap. In addition, the dielectric function and absorption coefficient as part of the investigation into the optical properties of these perovskites are calculated. The obtained results suggest that the two studied mixed halide perovskites have the capability to absorb electromagnetic radiation outside the visible spectrum, making them a promising candidate for potential uses in optoelectronic applications within the ultraviolet (UV) range.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Exchange interaction in metal oxides core-shell nanoparticles $$hbox {Co}_3hbox {O}_4$$ –CoO","authors":"S. Goswami, S. Chakravarty, M. Chakraborty, D. De","doi":"10.1007/s12648-024-03351-9","DOIUrl":"https://doi.org/10.1007/s12648-024-03351-9","url":null,"abstract":"<p>This article reports exchange bias (EB) effect in <span>(hbox {Co}_3hbox {O}_4)</span>–CoO nanoparticles despite having a ferromagnetic (FM) metal and antiferromagnetic (AFM) metal oxide interface. Pining mechanism in the overlapping domain of AFM spinel <span>(hbox {Co}_3hbox {O}_4)</span> and AFM CoO leads to a shift in magnetic hysteresis (<span>(M-H)</span>) loop towards the field axis followed by an increase in coercivity, when the system is cooled under static magnetic field − a typical signature of EB effect. Samples are prepared via sol–gel route followed by a controlled oxidation-reduction procedure; characterized via X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) analysis. Detailed studies of two samples of <span>(hbox {Co}_3hbox {O}_4)</span>–CoO show strong dependence of EB with a variation in crystallite size/phase fraction. Exchange interaction is maximum at lowest temperature and gradually vanishes above the AFM Néel temperature (<span>(T_N)</span>) of <span>(hbox {Co}_3hbox {O}_4)</span>. Another double interface ternary sample Co–<span>(hbox {Co}_3hbox {O}_4)</span>–CoO with FM Co at the center produces higher EB field than <span>(hbox {Co}_3hbox {O}_4)</span>–CoO nanostructures.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Prediction of spectral characteristics of lithium-like ions by artificial neural network","authors":"Salman Raza, Ahmed Ali Rajput, Mustaqeem Zahid, Shafiq Ur Rehman, Arif Akhtar Azam, Zaheer Uddin","doi":"10.1007/s12648-024-03346-6","DOIUrl":"https://doi.org/10.1007/s12648-024-03346-6","url":null,"abstract":"<p>An Artificial Neural Network has been employed to calculate spectral characteristics of lithium-like Beryllium (Be II), Boron (B III), Carbon (C 1V), and Nitrogen (N V) ions. The base data (input parameters) consisted of quantum defects and the inverse square of the principal quantum number of lithium atoms for calculating quantum defects and energies of lithium-like ions. The study has two parts; in the first part, the quantum defects of Lithium and lithium-like ions (Be II, B III, C 1V, and N V) were calculated using Quantum Defect Theory (QDT). In the second part, an Artificial Neural Network (ANN) with a single hidden layer and five neurons was utilized to predict lithium-like quantum defects. 70% of the data was used to train the network, and 15% was used for testing and validating the values of quantum defects up to n = 100 for each atom and ion. The extended Rydberg–Ritz formula was used to calculate the energies of the lithium-like elements.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 flux effects on generalized Klein-Gordon oscillator field in a topologically charged Ellis-Bronnikov-type wormhole","authors":"Faizuddin Ahmed, Houcine Aounallah, Prabir Rudra","doi":"10.1007/s12648-024-03340-y","DOIUrl":"https://doi.org/10.1007/s12648-024-03340-y","url":null,"abstract":"<p>The work primarily deals with the relativistic quantum dynamics of the oscillator field. It uses the generalized Klein-Gordon oscillator in an Ellis-Bronnikov-type wormhole space-time with a topological defect. The study involves deriving the radial wave equation and incorporating both Coulomb and Cornell-type potential functions. The analytical solution of the wave equation elucidates the influence of the topological defect of the geometry and the wormhole throat radius. The eigenvalue solution of the oscillator field highlights significant modifications to the results, underscoring the impact of the topological defect.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"The effects of electric fields and biaxial strain on the structural, electrical, magnetical, and optical properties of bulk and monolayer AgN","authors":"Jabbar M. Khalaf Al-zyadi, Mustafa M. Jaafar","doi":"10.1007/s12648-024-03312-2","DOIUrl":"https://doi.org/10.1007/s12648-024-03312-2","url":null,"abstract":"<p>By using the APW + lo approach within the context of density functional theory, the purpose of this research is to investigate the differences between the bulk and monolayer forms of AgN. An APW + lo approach, takes into account both electrons (core and valence) in a self-consistent manner throughout the process of full-potential treatment. A generalized gradient approximation and a structural model were used to conduct the analyses on the structural electronic, magnetic, and optical characteristics. Half-metallicity could be seen in the bulk form of the compound with an energy gap of 2.23 eV in the spin-up channel and an equilibrium lattice constant of 8.23 Å. In addition, the half-metallic behavior was maintained even after the crossover to the monolayer, which had an energy gap of 1.90 eV. In order to determine the band structures and the density of states that demonstrate the half-metallic character of the material, it is important to carry out an examination of the material's electronic properties. Rendering to the Slater-Pauling statute (Zt-4), the total magnetic moment equals 2 µ_B for each unit cell. The effect of the electric field and biaxial strain on a monolayer of AgN was also studied to calculate electronic, magnetic, and frequency-dependent optical properties such as, dielectric functions, reflectivity, absorption, optical conductivity, and energy loss. The findings highlighted that the AgN's monolayer is promise for spintronics applications.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Geodesic deviation analysis of time conformal Schwarzschild like black hole","authors":"Muhammad Saad Ghafar, Farhad Ali, Zahir Shah, Shahid Iqbal, Mansoor H. Alshehri","doi":"10.1007/s12648-024-03341-x","DOIUrl":"https://doi.org/10.1007/s12648-024-03341-x","url":null,"abstract":"<p>The astrophysical phenomena, for instance, the growth or decay of black holes (BHs), gravitational waves may continuously change the curvature of spacetimes. In addition, such phenomena also affect the thermodynamic structure of the sources over time. In this research, we examined the insertion of the time conformal factor <span>(e^{epsilon f(t)})</span> in the Renormalization Group Improved (RGI) Schwarzschild BH, without violating symmetry structure. We demonstrated that the curvature invariants, which are responsible for the spacetime structure around the time conformal Renormalization Group Improved Schwarzschild (TCRGIS) BH, depend explicitly on this time conformal factor. The parameter <span>(gamma)</span> that appeared in these invariants gives a complete radial profile of the square of the Ricci tensor, the Ricci scalar and the Kretschmann scalar. For positive values of <span>(gamma)</span> the behavior of the curvature of TCRGIS-BH is similar to both the RGI-BH and the Schwarzschild BH as it becomes infinite at center for <span>(gamma =0)</span>. Moreover, we have analyzed that the curvature invariants for TCRGIS BH decrease more rapidly as compared to both the RGI Schwarzschild BH and regular Schwarzschild BH, as a function of time.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Design and theoretical study of rectangular photonic crystal fiber based sensor for chemical sensing in terahertz regime","authors":"Deepak Garg, Jyotsna Singh, Ajeet Kumar","doi":"10.1007/s12648-024-03343-9","DOIUrl":"https://doi.org/10.1007/s12648-024-03343-9","url":null,"abstract":"<p>This paper presents the design and theoretical analysis of a photonic crystal fiber (PCF) based chemical sensor model. To evaluate the efficiency of this model, various optical parameters are analysed using finite element method based COMSOL Multiphysics Software. Different analytes namely methanol (1.317), water (1.330), ethanol (1.354) and benzene (1.366) have been considered for the sensing purpose in this study. The core region is infiltrated with different analytes separately. The model is simulated in THz regime (0.5–1.5 THz) to evaluate optical properties. The proposed structure design exhibits a high relative sensitivity of 96.85%, 97.32%, 97.99% and 98.33% for methanol, water, ethanol, and benzene, respectively at an operating frequency of 1.3 THz. The proposed model demonstrates exceptionally low confinement loss values which are 2.22 × 10^–12 dB/m for methanol, 1.16 × 10^–11 dB/m for water, 1.34 × 10^–11 dB/m for ethanol and is 1.30 × 10^–12 dB/m for benzene. Additionally, the effective material loss for the designed PCF also comes out to be very low for all the analytes, 0.0044 cm⁻¹ for methanol, 0.0040 cm⁻¹ water, 0.0034 cm⁻¹ for ethanol and 0.0032 cm⁻¹, for benzene. Furthermore, the PCF shows large effective mode area and numerical aperture (NA) within the mentioned range, at 1.3 THz. The NA values obtained at 1.3 THz are 0.32 for methanol, 0.40 for water, 0.32 for ethanol, and 0.32 for benzene. The obtained Effective mode Area (EMA) values are 1.46 × 10⁵ μm² for methanol, 1.45 × 10⁵ μm² for water, 1.44 × 10⁵ μm² for ethanol and 1.43 × 10⁵ μm², for benzene. Subsequently, the optimal profile provides birefringence values of 0.0009 for methanol, 0.0010 for water, and 0.0011 for both ethanol and benzene. The practical implementation of the proposed PCF structure is possible using subsisting modern fabrication techniques. Consequently, the proposed PCF design should be helpful in industrial areas for chemical research, food and biomedical sensing.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Mean first-passage time for a stochastic tumor growth model with two different time delays","authors":"Qin Yu, Yong-Feng Guo, Hao-Yu Chen","doi":"10.1007/s12648-024-03356-4","DOIUrl":"https://doi.org/10.1007/s12648-024-03356-4","url":null,"abstract":"<p>In this paper, the mean first-passage time (MFPT) of a stochastic tumor growth model driven by correlated white noises with two different time delays is investigated. The small time delay approximation is utilized to obtain the generalized potential function and the MFPT, and a detailed analysis is conducted on how time delays and noise parameters affect the generalized potential function and the MFPT, respectively. We further validate the effectiveness of the theoretical results using the fourth-order Runge–Kutta algorithm. The findings indicate that (1) when the intensity of multiplicative noise is higher and the intensity of additive noise is lower, there is a greater likelihood of tumor cells dying off, which promotes the healing of the system; (2) an increase in the correlation strength between multiplicative noise and additive noise promotes the carcinogenesis of tumor cells and accelerates the deterioration of the system; (3) increasing the time delay in the deterministic force and decreasing the time delay in the stochastic force lead to a higher likelihood of tumor cell extinction. Furthermore, the phenomenon of noise enhanced stability (NES) is found.</p>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141776773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}