Weaam AlhejailiEmad A Az-Zo'biRasool ShahS A El-Tantawy...
1-10页
查看更多>>摘要：The current investigation examines the fractional forced Korteweg-de Vries(FF-KdV)equation,a critically significant evolution equation in various nonlinear branches of science.The equation in question and other associated equations are widely acknowledged for their broad applicability and potential for simulating a wide range of nonlinear phenomena in fluid physics,plasma physics,and various scientific domains.Consequently,the main goal of this study is to use the Yang homotopy perturbation method and the Yang transform decomposition method,along with the Caputo operator for analyzing the FF-KdV equation.The derived approximations are numerically examined and discussed.Our study will show that the two suggested methods are helpful,easy to use,and essential for looking at different nonlinear models that affect complex processes.
查看更多>>摘要：By applying the mastersymmetry of degree one to the time-independent symmetry K1,the fifth-order asymmetric Nizhnik-Novikov-Veselov system is derived.The variable separation solution is obtained by using the truncated Painlevé expansion with a special seed solution.New patterns of localized excitations,such as dromioff,instanton moving on a curved line,and tempo-spatial breather,are constructed.Additionally,fission or fusion solitary wave solutions are presented,graphically illustrated by several interesting examples.
查看更多>>摘要：Collective quantum states,such as subradiant and superradiant states,are useful for controlling optical responses in many-body quantum systems.In this work,we study novel collective quantum phenomena in waveguide-coupled Bragg atom arrays with inhomogeneous frequencies.For atoms without free-space dissipation,collectively induced transparency is produced by destructive quantum interference between subradiant and superradiant states.In a large Bragg atom array,multi-frequency photon transparency can be obtained by considering atoms with different frequencies.Interestingly,we find collectively induced absorption(CIA)by studying the influence of free-space dissipation on photon transport.Tunable atomic frequencies nontrivially modify decay rates of subradiant states.When the decay rate of a subradiant state equals to the free-space dissipation,photon absorption can reach a limit at a certain frequency.In other words,photon absorption is enhanced with low free-space dissipation,distinct from previous photon detection schemes.We also show multi-frequency CIA by properly adjusting atomic frequencies.Our work presents a way to manipulate collective quantum states and exotic optical properties in waveguide quantum electrodynamics(QED)systems.
查看更多>>摘要：In this study,we focus into the non-relativistic wave equation described by the Schrödinger equation,specifically considering angular-dependent potentials within the context of a topological defect background generated by a cosmic string.Our primary goal is to explore quasi-exactly solvable problems by introducing an extended ring-shaped potential.We utilize the Bethe ansatz method to determine the angular solutions,while the radial solutions are obtained using special functions.Our findings demonstrate that the eigenvalue solutions of quantum particles are intricately influenced by the presence of the topological defect of the cosmic string,resulting in significant modifications compared to those in a flat space background.The existence of the topological defect induces alterations in the energy spectra,disrupting degeneracy.Afterwards,we extend our analysis to study the same problem in the presence of a ring-shaped potential against the background of another topological defect geometry known as a point-like global monopole.Following a similar procedure,we obtain the eigenvalue solutions and analyze the results.Remarkably,we observe that the presence of a global monopole leads to a decrease in the energy levels compared to the flat space results.In both cases,we conduct a thorough numerical analysis to validate our findings.
查看更多>>摘要：Higher dimensional entangled states demonstrate significant advantages in quantum information processing tasks.The Schmidt number is a quantity of the entanglement dimension of a bipartite state.Here we build families of k-positive maps from the symmetric information complete positive operator-valued measurements and mutually unbiased bases,and we also present the Schmidt number witnesses,correspondingly.At last,based on the witnesses obtained from mutually unbiased bases,we show the distance between a bipartite state and the set of states with a Schmidt number less than k.
查看更多>>摘要：Ultracold atoms endowed with tunable spin-orbital-angular-momentum coupling(SOAMC)represent a promising avenue for delving into exotic quantum phenomena.Building on recent experimental advancements,we propose the generation of synthetic gauge fields,and by including exotic vortex phases within spinor Bose-Einstein condensates,employing a combination of a running wave and Laguerre-Gaussian laser fields.We investigate the ground-state characteristics of the SOAMC condensate,revealing the emergence of exotic vortex states with controllable orbital angular momenta.It is shown that the interplay of the SOAMC and conventional spin-linear-momentum coupling induced by the running wave beam leads to the formation of a vortex state exhibiting a phase stripe hosting single multiply quantized singularity.The phase of the ground state will undergo the phase transition corresponding to the breaking of rotational symmetry while preserving the mirror symmetry.Importantly,the observed density distribution of the ground-state wavefunction,exhibiting broken rotational symmetry,can be well characterized by the synthetic magnetic field generated through light interaction with the dressed spin state.Our findings pave the way for further exploration into the rotational properties of stable exotic vortices with higher orbital angular momenta against splitting in the presence of synthetic gauge fields in ultracold quantum gases.
查看更多>>摘要：Following the recent paper(Teittinen et al 2019 New J.Phys.21 123041),one can see that in general there is no simple relation between non-Markovianity and quantum speed limit.Here,we investigate the connection between quantum speed limit time and non-Markovianity of an atom in structured environments(reservoirs)whose dynamics is governed by an exact pseudomode master equation(Garraway 1997 Phys.Rev.A 55 2290).In particular,we find an inverse relation between them,which means that the non-Markovian feature of the quantum process leads to speedup of evolution.Thus,there is a link between quantum speedup and memory effects for specific cases of dynamical evolution.Our results might shed light on the relationship between the speedup of quantum evolution and the backflow of information from the environment to the system.
查看更多>>摘要：We conducted a study on a simplified dark matter model that introduces a vector-like intermediate particle,facilitating exclusive interactions between dark matter and the top quark in the Standard Model.The analysis focused on the relic density of Dirac-type fermion dark matter and highlighted the complementary role of direct detection in constraining the dark matter model.Notably,in instances when dark matter mass is small,the tree-level two-body annihilation process experiences suppression.In such scenarios,the contributions of the three-body process(x(x) → t(b)W-)and the one-loop process(x(x)→gg)dominate the relic abundance.With regard to direct detection,calculations were performed for the two-loop contribution to the dark-matter-gluon interaction,yielding the corresponding spin-independent scattering cross section.
查看更多>>摘要：The structure of the irreducible collective spaces of the group Sp(12,R),which many-particle nuclear states are classified according to the chain Sp(12,R)⊃ U(6)⊃ SO(6)⊃ SUpn(3)(⊕)SO(2)⊃ SO(3)of the proton-neutron symplectic model(PNSM),is considered in detail.This chain of the PNSM was recently shown to correspond to a microscopic shell-model version of the Bohr-Mottelson collective model.The construction of the relevant shell-model representations of the Sp(12,R)group along this chain is considered for three nuclei with varying collective properties and from different mass regions.It is shown that the SUpn(3)basis states of the Sp(12,R)representations belonging to the SO(6)irreps with seniority v≥v0,with v0 denoting the maximal seniority SO(6)irrep contained in the Sp(12,R)bandhead,are always Pauli allowed,but organized in a different way into different SO(6)shells.This is in contrast to the case of filling the levels of the standard three-dimensional harmonic oscillator and using the plethysm operation.Although the SUpn(3)multiplets within v＜v0 are not all Pauli forbidden,it is safe to discard them.The results obtained in the present work are important for the practical application of the microscopic version of the Bohr-Mottelson collective model.
Ahmad Al-BadawiSanjar ShaymatovMirzabek AlloqulovAnzhong Wang...
91-102页
查看更多>>摘要：We investigate the impact of the modified gravity(MOG)field and the quintessence scalar field on horizon evolution,black hole(BH)shadow and the weak gravitational lensing around a static spherically symmetric BH.We first begin to write the BH metric associated with the MOG parameter and quintessence scalar field.We then determine the BH shadow and obtain numerical solutions for the photon sphere and shadow radius.We show that the MOG(α)and the quintessence(c)parameters have a significant impact on the BH shadow and photon sphere.Based on the analysis,we further show that the combined effects of the MOG parameter and quintessence field can increase the values of BH shadow and photon sphere radii.We also obtain constraints on the BH parameters by applying the observational data of Sgr A★ and M87★.Finally,we consider the weak deflection angle of BH within the context of the Gauss-Bonnet theorem(GBT)and show that the combined effects of the MOG and quintessence parameters do make the value of the deflection angle increase,and find this remarkable property is in good agreement with the physical meaning of both parameters that can maintain the strong gravitational field in the surrounding environment of a BH.
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