Pramana最新文献_第2页

Entanglement dynamics in two-proton decay of 12O and 6Be 12O和6Be双质子衰变中的纠缠动力学

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-09-10 DOI: 10.1007/s12043-026-03145-0

Hassan Khalili, Mahdi Azad Marzabadi

引用次数: 0

Pressure induced bandgap variation for the optical and photo-catalytic properties of MgA2X4 (A = Sc, Y; X = S, Se) spinel compounds 压力诱导带隙变化对MgA2X4 （A = Sc， Y; X = S, Se）尖晶石化合物光学和光催化性能的影响

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-09-02 DOI: 10.1007/s12043-026-03165-w

Zubaida Noor, G. Murtaza, Muhammad Awais Jehangir, Aijaz Rasool Chaudhry, Aurangzeb

{"title":"Pressure induced bandgap variation for the optical and photo-catalytic properties of MgA2X4 (A = Sc, Y; X = S, Se) spinel compounds","authors":"Zubaida Noor, G. Murtaza, Muhammad Awais Jehangir, Aijaz Rasool Chaudhry,  Aurangzeb","doi":"10.1007/s12043-026-03165-w","DOIUrl":"10.1007/s12043-026-03165-w","url":null,"abstract":"<div>Spinels possess excellent properties for use in advanced applications. Here in this study, using density functional theory (DFT) calculations, we have studied the structural, electronic and optical properties (dielectric function, electron energy loss, extinction coefficient, reflectivity and refractive index, absorption coefficient, optical conductivity) of spinel compounds of the form MgA2X4 (A = Sc/Y; X = S, Se) under the effect of applied pressure. Interesting physical variations were observed in these materials under the application of pressure. The generalised gradient approximation (GGA) method was performed to figure out structure optimisation. By adopting the modified Becke–Johnson (mBJ) exact exchange technique, electronic and optical properties were computed. The energy band gap is shrunken from 2.9 to 1.6 eV and 0.736 to 0.084 eV for MgA2X4 (A = Sc/Y; X = S, Se) compounds under the effect of pressure. A noticeable variation was seen in the lattice parameters, band gap, electronic and optical properties via exceeding the pressure from 0 to 20 GPa, featuring a prominent absorption coefficient and higher optical conductivity in the visible and UV region, showing greater potential for their use in high-frequency devices. The compounds have the appropriate band gaps for water splitting through redox reactions.</div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"100 3","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926705","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}

引用次数: 0

Numerical solutions for the MHD mixed convection flow of non-Newtonian nanofluid in a U-shaped enclosure 非牛顿纳米流体在u形外壳内MHD混合对流流动的数值解

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-31 DOI: 10.1007/s12043-026-03135-2

Sohail Nadeem, Aarif Hussain, Jehad Alzabut

{"title":"Numerical solutions for the MHD mixed convection flow of non-Newtonian nanofluid in a U-shaped enclosure","authors":"Sohail Nadeem, Aarif Hussain, Jehad Alzabut","doi":"10.1007/s12043-026-03135-2","DOIUrl":"10.1007/s12043-026-03135-2","url":null,"abstract":"<div>In this article, the mixed convection (natural and forced) heat transfer of non-Newtonian nanofluid (({text{Fe}}_{3}{text{O}}_{4})-water) steady-state, (2text{D}) flow, laminar, with the influence of a magnetic field in a baffled, U-shaped lid-driven cavity has been analyzed. The problem is modeled mathematically, and the resulting nonlinear partial differential equations are solved numerically using FEM. The cavity is heated by the baffles and cooled by the vertical walls (moving walls), while the other walls are adiabatic. Where Prandtl number ((Pr=6)) and Grashof number ((Gr=10000)) are assumed to be fixed. While the Richardson number is taken in the range of (0.01<Ri<100), the Hartmann number is taken in the range of 0 < Ha < 400, with an angle of inclination 0 < γ < π/2, and the power law index varies in the range of (0.6<n<1.4). The results are presented in terms of streamlines, isotherms and in line graphs, it is investigated that, the force convection is dominating the natural convection at low value of (Ri) while natural convection is dominating mechanism of heat transfer at higher values of (Ri) and a detailed study has been conducted for the various effects of (Ha,) (gamma ) and power law index on fluid flow and heat transfer. Also, it is observed that as the power-law index increases, the Nusselt number increases. For the convergence and validation of results, an artificial neural network is used and discussed.</div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"100 3","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928058","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}

引用次数: 0

Mid-infrared supercontinuum via tetrachloroethylene photonic crystal fiber with flat near-zero dispersion pumped at 1.55 µm 中红外超连续介质通过四氯乙烯光子晶体光纤，在1.55µm泵浦的平坦近零色散

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-26 DOI: 10.1007/s12043-026-03133-4

Duc Hoang Trong, Lanh Chu Van, Thuy Nguyen Thi

引用次数: 0

Exact solutions of scalar and coupled time-fractional nonlinear evolution equations with (varvec{x})-dependent coefficients using the invariant subspace method 用不变子空间方法精确解具有(varvec{x})依赖系数的标量和耦合时分数阶非线性演化方程

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-20 DOI: 10.1007/s12043-026-03154-z

C. Uma Maheswari, Supreet Kaur Bakshi

{"title":"Exact solutions of scalar and coupled time-fractional nonlinear evolution equations with (varvec{x})-dependent coefficients using the invariant subspace method","authors":"C. Uma Maheswari, Supreet Kaur Bakshi","doi":"10.1007/s12043-026-03154-z","DOIUrl":"10.1007/s12043-026-03154-z","url":null,"abstract":"<div>This work investigates the invariant subspace method for time-fractional nonlinear evolution equations of second order with x-dependent coefficients. The study focuses on identifying invariant subspaces admitted by these equations and provides a systematic framework for constructing explicit solutions. Applying this method, explicit solutions are found for the nonlinear reaction-diffusion-advection equation, the coupled Burgers equation, the coupled advection–diffusion equation, and many other scalar and coupled nonlinear partial differential equations with x-dependent coefficients and a time-fractional derivative. In particular, x-dependent coefficients involving polynomial functions are considered, and a classification of the time-fractional nonlinear partial differential equations is obtained based on the invariant subspaces admitted by them. The investigation demonstrates that the invariant subspace method is a powerful tool for obtaining exact solutions of time-fractional partial differential equations with variable coefficients, thereby revealing novel solution structures.</div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"100 3","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782581","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}

引用次数: 0

Special unitary algebras underlying bipartite qubit and qutrit systems 二部量子位和量子位系统下的特殊酉代数

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-20 DOI: 10.1007/s12043-026-03169-6

PRABAL DASGUPTA, DEBASHIS GANGOPADHYAY

{"title":"Special unitary algebras underlying bipartite qubit and qutrit systems","authors":"PRABAL DASGUPTA, DEBASHIS GANGOPADHYAY","doi":"10.1007/s12043-026-03169-6","DOIUrl":"10.1007/s12043-026-03169-6","url":null,"abstract":"<div>According to Ref. [11], in bipartite qubit systems, a matrix A exists such that (text {Det}, A = 0) indicates unentanglement, whereas (text {Det}, A ne 0) indicates entanglement, and there exists an underlying SU(2) algebra. Here, we show that this algebra does not imply any internal degrees of freedom. Physical interpretation of the underlying algebras is given for the SU(2) case in the context of two entangled electrons. We also show that under a certain redefinition of matrices, the Clifford algebra satisfied by the usual 4-dimensional Dirac matrices is obtained. This redefinition is related to time reversal. In Ref. [11] it was shown that for qutrits there is a matrix P for which (textrm{Det}, P =0 ) simultaneously with (textrm{Tr}, P = pm 1) implies unentanglement. Any departure from these conditions implies entanglement, and there exists an underlying ({ SU}(3)) algebra. The new results in this work are analytical solutions for the eigenvalues of the reduced density matrix corresponding to arbitrary bipartite qutrit states. The ({ SU}(3)) algebra is obtained after a redefinition of variables. Here, we also obtain the entanglement entropy for both qubits and qutrits. For qubits, the entropy is in terms of (textrm{Det},A). For qutrits the entropy is expressed in terms of (textrm{Det},P) and (textrm{Tr},P).</div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"100 3","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782580","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}

引用次数: 0

A class of lump type solutions related to an extended form of Kadomtsev–Petviashvili equation: Bilinear forms and interaction phenomena Kadomtsev-Petviashvili方程扩展形式的一类块型解：双线性形式和相互作用现象

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-11 DOI: 10.1007/s12043-026-03149-w

Zeeshan Amjad, Nauman Raza, Muhammad Shahbaz, Patricia J. Y. Wong, Younes Chahlaoui, Muhammad Farman

引用次数: 0

Continuous limit, conservation laws, modulation instability and analytical solutions for a three-component lattice equation 三分量晶格方程的连续极限、守恒定律、调制不稳定性和解析解

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-07 DOI: 10.1007/s12043-026-03139-y

Jian-Yu Liu, Xiao-Yong Wen

{"title":"Continuous limit, conservation laws, modulation instability and analytical solutions for a three-component lattice equation","authors":"Jian-Yu Liu, Xiao-Yong Wen","doi":"10.1007/s12043-026-03139-y","DOIUrl":"10.1007/s12043-026-03139-y","url":null,"abstract":"<div>This paper investigates a three-component lattice equation that generalizes classical nonlinear lattice systems such as the Volterra and Toda lattice equations. This equation integrates features of discrete structure and multi-component coupling and has wide-ranging applications in condensed matter physics, plasma physics, biological modeling, and engineering sciences. By imposing a continuous limit, we establish its correspondence with several continuous nonlinear equations. Subsequently, an infinite set of conservation laws is constructed from the Lax pair, revealing the underlying integrability of this system. Furthermore, starting from constant amplitude waves, we analyze the conditions for modulational instability (MI) and examine the parameter dependence of perturbation growth. Based on the associated linear spectral problem, the generalized ((n, N-n))-fold Darboux transformation (DT) is constructed. Applying this transformation yields rational solutions and mixed solutions on a non-zero seed background, and asymptotic analysis is performed to elucidate the dynamical behavior of rational solutions. These results contribute to a deeper understanding of nonlinear wave dynamics in multi-component lattice systems.\u0000</div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"100 3","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751367","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}

引用次数: 0

Constraining invisible neutrino decay at NO(nu )A and DUNE 在NO (nu ) A和DUNE上约束不可见中微子衰变

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-06 DOI: 10.1007/s12043-026-03167-8

Zannatun Firdowzy Dey, Debajyoti Dutta

{"title":"Constraining invisible neutrino decay at NO(nu )A and DUNE","authors":"Zannatun Firdowzy Dey, Debajyoti Dutta","doi":"10.1007/s12043-026-03167-8","DOIUrl":"10.1007/s12043-026-03167-8","url":null,"abstract":"<div>The main emphasis of this study is to explore the relevance of invisible neutrino decay within the frameworks of both the Deep Underground Neutrino Experiment (DUNE) and the NuMI off-axis (nu _{e}) appearance (NO(nu )A) experiments. Under the normal mass hierarchy, we suppose that (nu _3) is unstable and will eventually decay into a sterile state. In this work, we have studied the potential of these combinations to constrain the decay parameter. We have observed that the true value of (theta _{23}) can significantly affect the constraint on the decay parameter. A true value of (theta _{23}) in the HO can significantly improve the constraint. At the HO, for ({tau _3}/{m_3}=2times 10^{-11}) s/eV, DUNE and the combination of DUNE and NO(nu )A can rule out the no decay scenario at 3(sigma ) CL. For the given ({tau _3}/{m_3}), DUNE and the combination can measure ({tau _3}/{m_3}) at 3(sigma ), in the range [(7.22times 10^{-11}>{tau _3}/{m_3}> 1.16times 10^{-11})] s/eV and [(6.10times 10^{-11}>tau _{3}/m_{3}>1.19times 10^{-11})] s/eV, respectively. This precision measurement of ({tau _3}/{m_3}) improves significantly for the value of (theta _{23}) in the HO compared to the lower octant (LO). Our analysis also yields measurements of CP sensitivity for DUNE, NO(nu )A, and DUNE+NO(nu )A in the context of invisible neutrino decay. In this work, we consider three values of the decay parameter to illustrate the analysis.</div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"100 3","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751131","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}

引用次数: 0

Controlled remote implementation of operator via non-maximal hyperentanglement and its relevance 非极大超纠缠算子的远程控制实现及其相关性

IF 2.3 4区物理与天体物理

Pramana Pub Date : 2026-08-06 DOI: 10.1007/s12043-026-03170-z

Cao Thi Bich, Nguyen Ba An

{"title":"Controlled remote implementation of operator via non-maximal hyperentanglement and its relevance","authors":"Cao Thi Bich, Nguyen Ba An","doi":"10.1007/s12043-026-03170-z","DOIUrl":"10.1007/s12043-026-03170-z","url":null,"abstract":"<div>Controlled remote implementation of an operator (CRIO) is a global quantum protocol for executing an unknown unitary operator on a distant, unknown quantum state under the control of a remote controller, using a quantum resource shared in advance between the implementers and the controller. One implementer (Alice) has a photon in an unknown state to everyone. The other implementer (Bob) has a general unitary operator that he can execute, but no one else can. The controller (Charlie) does not need to know the explicit forms of both Alice’s state and Bob’s operator, but reserves the right to decide when the CRIO completes, i.e., when the remote implementation of Bob’s operator on Alice’s state is complete. Such protocols are fundamentally needed for controllable, scalable quantum distributed computing and cloud-based applications across remote nodes within a quantum network. In this paper, we extend our work (An and Bich, J. Phys. A: Math. Theor. 55, 225307 (2022)), in which a maximally hyperentangled state was used as the quantum resource, to the case of non-maximal hyperentanglement. The parameters identifying the non-maximally hyperentangled state of the quantum resource are deliberately configured to be known exclusively to the controller, ensuring a high level of security. We show that, although the shared hyperentangled state is non-maximal, the controller can still effectively govern the CRIO protocol, achieving unit fidelity at the expense of a finite success probability. This success probability is proportional to the degree of entanglement of the quantum resource, which can be flexibly tuned by appropriate channel engineering. Furthermore, we derive the average fidelity of classical remote implementation of the operator and calculate the average non-conditioned fidelity of the quantum CRIO without the controller’s participation. Then we evaluate the relevance of the quantum protocol in terms of the so-called quantumness power and the controller’s power.</div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"100 3","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751132","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}

引用次数: 0