Orbital Angular Momentum of Light Research Papers (original) (raw)

2025, Classical and Quantum Gravity

The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of

2025, Physical Review C

Isomeric yield ratios for the reactions ' Ag(a, 3n)' In, ' Ag(a, a3n)' Ag, ' Ag(a, 2n)"'In, and Ag(a, 3n)" In are determined in the energy range of 20-63 MeV a particles. Excitation functions for the above reactions as well as for the ' Ag(a, 2n ) ' In, ' Ag(a, a2n )' Ag, ' Ag(a, 4n ) ' In, Ag(a, 5n)' 'In, and ' Ag(a, a4n)' 'Ag reactions are also presented. Experimental excitation functions are compared with statistical model calculations taking into account precompound particle emission. Isomeric yield ratios are found to depend strongly on the root mean square orbital angular momentum in the entrance channel. A semiempirical method for the prediction of isomeric yield ratios failed to repro- duce experimental data even for compoundlike reactions. Isomeric yield ratios were also calculated in the frame of a statistical model under consideration of angular momentum effects in the preequilibrium and the equilibrium stage. Overall agreement between the theory and the experiment for isomeric yield ratios was found to be satisfactory especially at low bombarding energy when compound nucleus reac- tion channel is dominant. The discrepancy observed at higher bombarding energies needs to be theoreti- cally investigated in greater detail.

2025, Physical Review Letters

2025, Acta Physica Polonica Series B

Disturbing of a spacetime geometry may result in the appearance of an oscillating and damped radiation -the so-called quasinormal modes. Their periods of oscillations and damping coefficients carry unique information about the mass and the angular momentum, that would allow one to identify the source of the gravitational field. In this talk we present recent bounds on the diffused energy, applicable to the Schwarzschild spacetime, that give also rough estimates of the energy of excited quasinormal modes.

2025, Physical Review D

We present a deep-learning artificial intelligence model that is capable of learning and forecasting the late-inspiral, merger and ringdown of numerical relativity waveforms that describe quasi-circular, spinning, non-precessing binary black hole mergers. We used the NRHybSur3dq8 surrogate model to produce train, validation and test sets of = |m| = 2 waveforms that cover the parameter space of binary black hole mergers with mass-ratios q ≤ 8 and individual spins |s z {1, 2} | ≤ 0.8. These waveforms cover the time range t ∈ [-5000M, 130M], where t = 0M marks the merger event, defined as the maximum value of the waveform amplitude. We harnessed the ThetaGPU supercomputer at the Argonne Leadership Computing Facility to train our AI model using a training set of 1.5 million waveforms. We used 16 NVIDIA DGX A100 nodes, each consisting of 8 NVIDIA A100 Tensor Core GPUs and 2 AMD Rome CPUs, to fully train our model within 3.5 hours. Our findings show that artificial intelligence can accurately forecast the dynamical evolution of numerical relativity waveforms in the time range t ∈ [-100M, 130M]. Sampling a test set of 190,000 waveforms, we find that the average overlap between target and predicted waveforms is 99% over the entire parameter space under consideration. We also combined scientific visualization and accelerated computing to identify what components of our model take in knowledge from the early and late-time waveform evolution to accurately forecast the latter part of numerical relativity waveforms. This work aims to accelerate the creation of scalable, computationally efficient and interpretable artificial intelligence models for gravitational wave astrophysics.

2025, Journal of Sciences, Islamic Republic of Iran

We study entanglement in coherent spin states and several superpositions of multi-qutrit coherent states evolved under the one-axis counter-twisting Hamiltonian in the presence and absence of a magnetic field. Considering a non-entangled multi-qutrit spin coherent state as an initial one, it is found that the entanglement is instigated with an oscillatory behavior in time; however, its average is a decreasing function of the magnetic field. Also, we observe that under this Hamiltonian, the two-qutrit superposed state retains its maximum entanglement with no change, while, the negativity for the three-qutrit superposed state oscillates in time and its average increases in the presence of the magnetic field.

2025, Bulletin of the American Physical Society

Rotation of an optical angular interference pattern in a spiral phase plate etalon YISA RUMALA, AARON LEANHARDT, University of Michigan, Ann Arbor -A spiral phase plate etalon fabricated from a transparent polymer with azimuthally varying thickness and non-zero reflectivity at both surfaces is used to create an optical angular interference pattern on the output plane of the device [1]. The angular interference pattern is observed to rotate as the laser frequency is varied, and compared to a computer model of the experiment based on shot noise limited assumptions. For an ultra-low finesse device, the angular interference pattern is calculated to rotate through a 2π radian angle when the laser frequency is varied by ∼100GHz with a sensitivity of a few MHz (∼0.1π milli radian rotation angle) as determined from fitting the data. This work extends the operation of the conventional Fabry-Perot etalon consisting of longitudinal interference fringes to include angular interference fringes, and is expected to have broad applications in optical frequency metrology, quantum optics and coherent control of atomic systems. [1] Y.S. Rumala and A. E. Leanhardt, "Multiple beam interference in spiral phase plates", (APS DAMOP) Bull. Am. Phys. Soc. 56, No. 5, p.170, 2011 (Full manuscript in preparation).

2025

Vortex states are interesting fundamental quantum states whilst also finding many uses in photon optics. In 2010, propagating electron vortices were experimentally produced for the first time leading to the emergence of the field of electron phase shaping. This thesis details the production of electron states containing orbital angular momentum which produce a C-shaped intensity in the focal plane. This C-shaped intensity has a diameter of approximately 10 nm and can be used to lithographically pattern nanometre scale split rings. The broken rotational symmetry also allows rotations to be viewed. The design theory and orbital angular momentum analysis of the C-shaped states is presented. Experimental results of the first production of C-shaped electrons are then shown. The C-shaped electron beams have been applied to lithographic patterning and future potential applications of C-shapes for both electrons and photons are discussed. Photons have been shown to be able to couple total a...

2025, Optics Express

We present an optomechanical device designed to allow optical transduction of orbital angular momentum of light. An optically induced twist imparted on the device by light is detected using an integrated cavity optomechanical system based on a nanobeam slot-mode photonic crystal cavity. This device could allow measurement of the orbital angular momentum of light when photons are absorbed by the mechanical element, or detection of the presence of photons when they are scattered into new orbital angular momentum states by a sub-wavelength grating patterned on the device. Such a system allows detection of a l = 1 orbital angular momentum field with an average power of 3.9 × 10 3 photons modulated at the mechanical resonance frequency of the device and can be extended to higher order orbital angular momentum states.

2025, Physical Review Letters

We present the first measurement of the Q 2 -dependence of the neutron spin structure function g n 2 at five kinematic points covering 0.57 (GeV/c) 2 ≤ Q 2 ≤ 1.34 (GeV/c) 2 at x ≃ 0.2. Though the naive quark-parton model predicts g2 = 0, non-zero values occur in more realistic models of the nucleon which include quark-gluon correlations, finite quark masses or orbital angular momentum. When scattering from a non-interacting quark, g n 2 can be predicted using next-to-leading order fits to world data for g n 1 . Deviations from this prediction provide an opportunity to examine QCD dynamics in nucleon structure. Our results show a positive deviation from this prediction at lower Q 2 , indicating that contributions such as quark-gluon interactions may be important. Precision data obtained for g n 1 are consistent with next-to-leading order fits to world data.

2025

It has been known for a century that electromagnetic fields can transport not only energy and linear momentum but also angular momentum. However, it was not until twenty years ago, with the discovery in laser optics of experimental techniques for the generation, detection and manipulation of photons in well-defined, pure orbital angular momentum (OAM) states, that twisted light and its

2025

In this paper, effective g -factors of the electronsin Kane type GaAs semiconductor in the infinite potential wellin the presence electric field and magnetic field have been calculated. The magnetic field was applied parallel to interfaces in the z direction and electric field F was applied perpendicularly to the interfaces along the y direction. g-factor as a function of the oscillation center was constant for ground state andparabolic for first excited in uniform magnetic field was without electric field. When the electric field was present, Landefactor according to oscillation center decreased linearly for ground state and was non parabolic for first exited level in uniform magnetic field. We have found out that g-factor increase as the electric field increase

2025, Micromachines

Silicon carbide (SiC) is a very promising platform for quantum information processing, as it can host room temperature solid state defect quantum bits. These room temperature quantum bits are realized by paramagnetic silicon vacancy and divacancy defects in SiC that are typically introduced by irradiation techniques. However, irradiation techniques often introduce unwanted defects near the target quantum bit defects that can be detrimental for the operation of quantum bits. Here, we demonstrate that by adding aluminum precursor to the silicon and carbon sources, quantum bit defects are created in the synthesis of SiC without any post treatments. We optimized the synthesis parameters to maximize the paramagnetic defect concentrations—including already established defect quantum bits—monitored by electron spin resonance spectroscopy.

2025, International Journal of Modern Physics E

The mixing of the quasifission component to the fissionlike cross section causes ambiguity in the quantitative estimation of the complete fusion cross section from the observed angular and mass distributions of the binary products. We show that the partial cross section of quasifission component of binary fragments covers the whole range of the angular momentum values leading to capture. The calculated angular momentum distributions for the compound nucleus and dinuclear system going to quasifission may overlap: competition between complete fusion and quasifission takes place at all values of initial orbital angular momentum. Quasifission components formed at large angular momentum of the dinuclear system can show isotropic angular distribution and their mass distribution can be in mass symmetric region similar to the characteristics of fusion-fission components. As result the unintentional inclusion of the quasifission contribution into the fusion-fission fragment yields can lead t...

2025, Journal of the Physical Society of Japan

The influence of the orientation angles of the target nucleus symmetry axis relative to the beam direction on the production of the evaporation residues is investigated for the 48 Ca+ 154 Sm reaction as a function of the beam energy. At low energies (E c.m. <137 MeV), the yield of evaporation residues is observed only for collisions with small orientation angles (α T < 45 0 ). At large energies (about E c.m. =140-180 MeV) all the orientation angles α T can contribute to the evaporation residue cross section σ ER in the 10-100 mb range, and at E c.m. >180 MeV σ ER ranges around 0.1-10 mb because the fission barrier for a compound nucleus decreases by increasing its excitation energy and angular momentum.

2025, Chaos, Solitons & Fractals

This paper investigates the interaction between orbital angular momentum (OAM) beams and a three-level closed-loop atomic system, focusing on how the azimuthal distribution of population is influenced by relative phase, OAM number, and magnetic field detuning. We explore the effect of OAM beam, characterized by their helical phase structure, on atomic transitions, specifically examining how the vortex beam induces spatially dependent population distributions in the atomic system. Our result shows that when the relative phase between the probe and vortex field is nonzero, the population distribution exhibits azimuthal dependence. In contrast, for zero relative phase, the population distribution leads to 2D localization of atoms at the center of the azimuthal plane, offering a novel method for atom localization. The effect of detuning the magnetic field is also examined, showing that nonzero detuning causes asymmetric azimuthal population distributions, with peaks and dips emerging as detuning increases. These results provide valuable insights into the role of structured light fields in quantum systems, offering potential applications in areas such as quantum information processing, atom localization, and precision control of atomic systems.

2025, Optics Letters

An approach based on the two-channel moiré deflectometry has been used to measure both wavefront and transverse component of the Poynting vector of an optical vortex beam. Generated vortex beam by the q-plate, an inhomogeneous liquid crystal cell, has been analyzed with such technique. The measured topological charge of generated beams are in an excellent agreement with theoretical prediction.

2025, Journal of the Optical Society of America B

For convenient optical communications by the aid of vortex beams, topological charge (TC) alterations should be translated to the change in intensity of the output light. In this paper, we formulate and experimentally investigate diffraction of vortex beams from amplitude radial gratings having sinusoidal profiles. We show that the diffraction pattern simply renders both TC and twist direction of the impinging vortex beam. When the TC of the vortex beam and the radial grating spoke number are equal, intensity on the optical axis of the Fraunhofer pattern gets a maximum value. Otherwise, its value on the optical axis remains zero. We examined the method on different vortex beams; the measured TCs of generated beams are in excellent agreement with the expected values. We show that an alteration between two vortex beams, in which one has a TC equal to the grating spoke number, is translated to a binary change in intensity of the output light on the optical axis. This feature might find wide applications in optical communications.

2025, Physical Review A

It is shown that the momentum density of free electromagnetic field splits into two parts. One has no contribution to the net momentum due to the transversality condition. The other yields all the momentum. The angular momentum that is associated with the former part is spin, and the angular momentum that is associated with the latter part is orbital angular momentum. Expressions for the spin and orbital angular momentum are given in terms of the electric vector in reciprocal space. The spin and orbital angular momentum defined this way are used to investigate the angular momentum of nonparaxial beams that are described in a recently published paper [Phys. Rev. A 78, 063831 (2008)]. It is found that the orbital angular momentum depends, apart from an l-dependent term, on two global quantities, the polarization represented by a generalized Jones vector and a new characteristic represented by a unit vector I, though the spin depends only on the polarization. The polarization dependence of orbital angular momentum through the impact of I is obtained and discussed. Some applications of the result obtained here are also made. The fact that the spin originates from the momentum density that has no contribution to the net momentum is used to show that there does not exist the paradox on the spin of circularly polarized plane wave. The polarization dependence of both spin and orbital angular momentum is shown to be the origin of conversion from the spin of a paraxial Laguerre-Gaussian beam into the orbital angular momentum of the focused beam through a high numerical aperture.

2025, Optics Express

In this paper we discuss the conservation of angular momentum of light in single scattering of circularly polarized light from a spherical, non-absorbing particle. We show that the angular momentum carried by the incident wave is distributed in the scattered waves between terms related to polarization or spin and to orbital angular momentum, respectively. We also show that, in all scattering directions, a constant ratio exists between the flux density of the total angular momentum and the intensity.

2025, Optics Letters

We propose a fiber structure of a square core and ring refractive index profile that converts an input circular polarized Gaussian mode into optical orbital angular momentum (OAM) modes. By breaking the circular symmetry of the waveguide, the input circularly polarized fundamental mode in the square core can be coupled into the ring region to generate higher-order OAM modes, corresponding to the transference of spin angular momentum and orbital angular momentum. We show, by using simulation, the generation of OAM modes with a topological charge l up to 9 using <10 mm long fiber. The mode purity is above 96.4% and the extinction ratio can be 30 dB.

2025

We have measured the linear ( P1 ) and circular ( P3 ) polarization of the fluorescence emitted in the , ^2sigmau^+ ->, ^2sigmag^+ ;( nu'=0,nu''=0 ) transition (391.4 nm) of N2^+ after photoionization of N2 by both linearly and circularly polarized VUV radiation. The value of P1 for linearly polarized excitation is in qualitative agreement with previous results [1]. Results for circularly-polarized excitation show significantly different energy dependence. In this energy range, photofragmentation into neutral atoms caused by the predissociation of doubly-excited Rydberg states via non-Rydberg doubly-excited resonances competes with photoionization [2]. We have measured the intensity and a distinct non-zero P3 of the fluorescence from the NI,p,^4P^o->3s,^4P,transition (818 nm) between 22.5 and 25 eV which corresponds to the initial excitation of the N2 Rydberg R(C) states. [1] J. A. Guest et al., Phys. Rev. A 28, 2217 (1983) [2] P. Erman et al., Phys. Rev. A 60, ...

2025, Journal of Plasma Physics

Both spin and orbital angular momentum can be exchanged between a rotating wave and a rotating magnetized plasma. Through resonances the spin and orbital angular momentum of the wave can be coupled to both the cyclotron rotation and the drift rotation of the particles. It is, however, shown that the Landau and cyclotron resonance conditions which classically describe resonant energy-momentum exchange between waves and particles are no longer valid in a rotating magnetized plasma column. In this case a new resonance condition which involves a resonant matching between the wave frequency, the cyclotron frequency modified by inertial effects and the harmonics of the guiding centre rotation is identified. A new quasilinear equation describing orbital and spin angular momentum exchanges through these new Brillouin resonances is then derived, and used to expose the wave-driven radial current responsible for angular momentum absorption.

2025, Journal of Plasma Physics

Rotational Fresnel drag -or orbital Faraday rotation -in a rotating magnetised plasma is uncovered and studied analytically for Trivelpiece-Gould and Whistler-Helicon waves carrying orbital angular momentum (OAM). Plasma rotation is shown to introduce a nonzero phase shift between OAM-carrying eigenmodes with opposite helicities, similarly to the phase-shift between spin angular momentum eigenmodes associated with the classical Faraday effect in a magnetised plasma at rest. By examining the dispersion relation for these two low-frequency modes in a Brillouin rotating plasma, this Faraday-Fresnel rotation effect is traced back to the combined effects of Doppler shift, centrifugal forces and Coriolis forces. In addition, rotation is further shown to lead to rotation-and azimuthal mode-dependent longitudinal group velocity, therefore prediciting the Faraday-Fresnel splitting of the enveloppe of a wave packet containing a superposition of OAMcarrying eigenmodes with opposite helicities.

2025, International Journal of Theoretical Physics

We discuss a type of measurement in which a macroscopically large angular momentum (spin) is "created" nonlocally by the measurement of just a few atoms from a double Fock state. This procedure apparently leads to a blatant nonconservation of a macroscopic variable -the local angular momentum. We argue that while this gedankenexperiment provides a striking illustration of several counter-intuitive features of quantum mechanics, it does not imply a non-local violation of the conservation of angular momentum.

2025, Optics Express

The torque exerted by an astigmatic optical beam on small transparent isotropic particles was dynamically measured observing the angular motion of the particles under a microscope. The data confirmed that torque was originated by the transfer of orbital angular momentum associated with the spatial changes in the phase of the optical field induced by the moving particle. This mechanism for angular momentum transfer works also with incident light beams with no net angular momentum.

2025

2025, Physical Review A

We study the field generated in the outer space by the superposition of modes of a regular circular monomode fiber array. It is shown that a supermode of the fiber array generates a discrete optical vortex; the formula for the topological charge of the vortex is obtained depending on the order of the supermode and the number of fibers in the array. The orbital angular momentum carried by an arbitrary superposition of supermodes is shown to equal the weighted sum of partial angular momenta of supermodes. It is shown that for certain combinations of supermodes the angular momentum comprises along with its intrinsic part also the extrinsic constituent. For such combinations precession of the angular momentum about the propagation axis is demonstrated. It is demonstrated that by combining supermodes one can generate in the array stable regularly rotating linear azimuthons. By creating a phased excitation of certain groups of fibers in the array one can control the global soliton-like motion of the excited domain.

2025, Physical Review A

We study energy transfer and orbital angular momentum of supermodes in a double-ring array of evanescently coupled monomode optical fibers. The structure of supermodes and the spectra of their propagation constants are obtained. The geometrical parameters of the array, at which the energy is mostly confined within the layers, are determined. The developed method for finding the supermodes of concentric arrays is generalized for the case of multiring arrays. The orbital angular momentum carried by a supermode of a double-ring array is calculated. The discrete lattice current is introduced. It is shown that the sum of discrete currents over the array is a conserved quantity. The connection of the total discrete current with orbital angular momentum of discrete optical vortices is made.

2025, Optics Letters

We have studied the effect of a twist defect on the conversion of the fundamental mode (FM) into an optical vortex (OV) in a helical-core fiber (HCF). We have shown that if such a twist defect is situated in the middle of the HCF, which converts the FM into an OV, such a fiber system can continuously change the orbital angular momentum (OAM) of the output field from 0 to 1 (in a.u.). This control of the OAM is achieved by variation of the twist angle. In this action upon the OAM, this system has analogy with the quarter-wave plate, which is able to change the spin angular momentum. We also introduced the generalized Stokes parameters (SPs) and Poincaré sphere to visualize evolution of the superposition of states with zero and nonzero OAM. Connection of SPs with geometric characteristics of the location of singularity is made.

2025, Physical Review Letters

It is experimentally demonstrated that a circularly polarized laser beam normally incident on a homeotropically aligned nematic film can induce a collective precession of the molecules in the film if the laser intensity is above the threshold for the Freedericksz transition. The effect is shown to result from a transfer of angular momentum from the laser beam to the medium.

2025, American Journal of Physics

We describe a simple but quantitative experiment to demonstrate the conservation of angular momentum. We measure the correlation of the apparent radius and angular velocity of the Sun with respect to the stars, due to the conservation of the angular momentum of Earth in its orbit. We also determine the direction of Earth's angular momentum vector and show that it is conserved. The experiment can be performed using a small telescope and a digital camera. It is conceptually simple, allowing students to get direct physical insight from the data. The observations are performed near the resolution limit imposed by the atmosphere, and in the presence of strong competing effects. These effects necessitate a careful experimental setup and allow students to improve their skills in experimentation.

2025

We present the results of six self consistent cosmological simulations to investigate the shape and kinematic evolution of elliptical-like objects (hereafter E) at several redshifts. In the present analysis, we consider three dimensional... more

2025, Optica

The creation of optically powered self-assembling nano-to-meso-scale machines that do work is a long-standing goal in photonics. We demonstrate an optical matter (OM) machine that converts the spin angular momentum (SAM) of light into orbital angular momentum (OAM) to do mechanical work. The specific OM machine we study is based on a sixfold symmetric hexagonally ordered nanoparticle array that operates as an OM "gear" that is assembled and made to rotate in a circularly polarized Gaussian beam. The rotational symmetry of the OM gear leads to a selection rule for the allowed scattering modes based on their angular momentum. Electrodynamics calculations show that the collective scattering modes with the largest angular momentum scatter strongly in the transverse direction. Simulations and experiments show that the angular momentum that accompanies the scattered light causes a "negative torque" response on the OM gear and drives a "probe" particle placed outside the OM gear around the gear in an asymmetric force field analogously to Brownian ratchets. The gear-probe OM machine concept can be expanded to applications in nanofluidics and particle sorting.

2025, Optics Express

Previous work by Allen, demonstrated that optical beams possess orbital angular momentum. Other work has shown that a random, phase-only disturbance can impart ±1 orbital angular momentum states to propagating waves. However, the field preceding the formation of these ±1 states was unknown. In this paper, we identify the unique field that leads to the formation of a pair of branch points, indicators of orbital angular momentum. This field is then verified in a bench-top optical experiment.

2025, Optics Express

This report was cleared for public release by the 377' 11 Air Base Wing Public Mfairs Office and is avai lable to the general public, including forei gn nationals. Copies may be obtained from the Defense Technical Information Center... more

2025, Proceedings of SPIE

We present an introduction to the orbital angular momentum of light for use in optics instruction. This type of angular momentum is a new fundamental concept discovered fifteen years ago. It arises in optical beams with helical wave-fronts. We introduce it as part of a fundamental discussion of the momentum of light. We also present inexpensive demonstrations of transfer of linear and angular momentum of light using optical tweezers.

2025, Physical Review A

We set forth a method to analyze the orbital angular momentum of a light field. Instead of using the canonical formalism for the conjugate pair angle-angular momentum, we model this latter variable by the superposition of two independent harmonic oscillators along two orthogonal axes. By describing each oscillator by a standard Wigner function, we derive, via a consistent change of variables, a comprehensive picture of the orbital angular momentum. We compare with previous approaches and show how this method works in some relevant examples.

2025, Proceedings of SPIE

The propensity of conventional optical beams to convey angular momentum is very well known. As a spin-1 elementary particle any photon can assume a polarisation state with a well defined 'spin' angular momentum of plus or minus 1 in the direction of propagation, corresponding to a circular polarisation of either left or right helicity. The mechanical effects of photonic angular momentum are manifest in a variety of phenomena operating at both the atomic and macroscopic scale. Photon angular momentum also exercises a key role in atomic spectroscopy and a host of other fundamental optical phenomena. The aim of this work is to study the interaction between matter and Laguerre-Gaussian beams, and others of related structure in which a helical wavefront confers an endowment with 'orbital' angular momentum. Although the principles and methods of production of these twisted beams are already quite well understood, the detailed study of the interactions is a novel subject. We explore changes in selection rules transfer of linear and angular momentum in the context of nonlinear processes, especially harmonic and sum-frequency generation.

2024, European Physical Journal Plus

We have recently 1 argued that classical electrodynamics can predict nonlocal effects by showing an example of a topological and nonlocal electromagnetic angular momentum. In this paper we discuss the dual of this angular momentum which is also topological and nonlocal. We then unify both angular momenta by means of the electromagnetic angular momentum arising in the configuration formed by a dyon encircling an infinitely-long dual solenoid enclosing uniform electric and magnetic fluxes and show that this electromagnetic angular momentum is topological because it depends on a winding number, is nonlocal because the electric and magnetic fields of this dual solenoid act on the dyon in regions for which these fields are excluded and is invariant under electromagnetic duality transformations. We explicitly verify that this duality-invariant electromagnetic angular momentum is insensitive to the radiative effects of the Liénard-Wiechert fields of the encircling dyon. We also show how duality symmetry of this angular momentum suggests different physical interpretations for the corresponding angular momenta that it unifies.

2024, Bulletin of the American Physical Society

2024, International Journal of Quantum Information

We discuss a scheme for a full superdense coding of entangled photon states employing only linear-optics elements. By using the mixed basis consisting of four states that are unambiguously distinguishable by a standard and polarizing beam splitters we can deterministically transfer four messages by manipulating just one of the two entangled photons. The sender achieves the determinism of the transfer either by giving up the control over 50% of sent messages (although known to her) or by discarding 33% of incoming photons.

2024, arXiv (Cornell University)

We present a scheme for a full superdense coding of entangled photon states employing only linear-optics elements. By using the mixed basis consisting of four states that are unambiguously distinguishable by a standard and polarizing beam splitters we can deterministically transfer four messages by manipulating just one of the two entangled photons. The experimental feasibility of the scheme is discussed and we show that with the presently available technology one can transfer over 1.97 and 1.72 bits in two different superdense coding schemes, respectively.

2024, International Journal of Grid Computing & Applications

Computer Technology has Revolutionized Science. This has motivated scientists to develop mathematical model to simulate salient features of Physical universe .These models can approximate reality at many levels of scale such as atomic nucleus, Earth's biosphere & weather/climate assessment. To solve these type of complex problems in usable time frame , there is a need of high performance powerful computer mechanism which can do the calculations in a time bound with high precision. If the computer power is greater, the greater will be the accuracy in approximation i.e. close will be the approximation to the reality. The speed of the computer required for solution of such problems require computers with processing power of teraflops to Pets flops speed.. The way to speed up the computation is to "parallelize" it i.e. divide the work into modules that can be worked on by separate processors at the same time. Thus we can solve the problems that are Non-Polynomial form in polynomial time. One of the approach is to use multimillion dollar Supercomputer or use Computational Grid ( Which is also called poor man's supercomputer) having geographically distributed resources e.g. SETI@home (Used to detect radio waves emitted by intelligent civilizations outside earth) has 4.6 million participants computers. There are many alternatives tools available to achieve this goal like Globus Toolkit, Entropia, Legion, BOINC etc but they are mainly based on Linux platform. As majority of the computers available are windows based, so it will be easy to develop a larger network of computers which will use the free cycles of the computer to solve the complex problem at window platform. Nimble@ITCEcnoGrid has been developed. It includes the feature of Inter Thread Communication which is missing in any of the toolkits available. Nimble@ITCEcnoGrid Framework (A Fast Grid with Inter-thread communication with Economic Based Policy) was tested for computation of 'PI' up to 120 decimal points. Encouraged by the speed the same system has been utilized to computes the Momentum, Thermodynamics and Continuity equations for the Weather Forecasting using the Windows based Desktop computers..

2024, Physical Review C

From coincidence measurements between projectile-like fragments or heavy residues and their as- sociated y rays, the angular momentum transfers for a variety of incomplete fusion reactions of 180 and 310 MeV ' 0 with ' Sm have been derived. At the higher energy, the correlation between an- gular momentum transfer and linear momentum transfer has been obtained over the entire range of linear momentum transfer. A comparison of the data with calculations of both the sum-rule and geometric overlap models indicates that each makes reasonable predictions of the observed trend even though the assumptions of the models are quite different, and very different initial partial waves are predicted to contribute to particular reaction channels. This results primarily from prescriptions relating fractional mass transfer to fractional angular momentum transfer. The recon- struction of the initial partial wave distributions from correlated measurements of linear momentum and angular momentum transfers is addressed. Comparisons are also made with more recent model calculations which focus on nucleon-nucleon scattering as the mechanism of momentum transfer.

2024, Modern Physics Letters A

The gross features of the observed baryon excitation spectrum below 2 GeV are well explained if the spectrum generating algebra of its intrinsic orbital angular momentum states is o(4)⊗su(2)I . The spins of the resonances are obtained through the coupling of a Lorentz bi-spinor { 1 2 , 0} ⊕ {0, 1 2 } to a multiplet of the type {j, j} in its O(4)/O(3) reduction. The parities of the resonances follow from those of the O(3) members of the {j, j} multiplets. In this way relativistic SL(2,C) representations are constructed. For example, the first S11, P11, and D13 states with masses around 1500 MeV fit into the The observed parities of the resonances correspond to natural parities of the { 1 2 , 1 2 } states. The second P11, S11, D13 -together with the first P13, F15, D15, and (a predicted) F17-resonances, centered around 1700 MeV, are organized into the }] representation. I argue that the members of the { 3 2 , 3 2 } multiplet carry unnatural parities and that in this region chiral symmetry is restored. In the N (939) → N (1650) transition the chiral symmetry mode is changed, and therefore, a chiral phase transition is predicted to take place.

2024, arXiv (Cornell University)

It is argued that the baryon excitations group to four-dimensional partial waves described by means of the three Rarita-Schwinger (RS) fields and, where all components happen to be occupied. In the O(4) decomposition of the πN scattering amplitudes, the RS spin-and parity clusters appear as poles on the complex energy plane, socalled Höhler poles. This phenomenon indicates that the symmetry of the πN scattering amplitude is O(4) and thereby the space-time version of chiral symmetry, rather than O(3). Accordingly, the baryon spectrum generating algebra is su(2)I ⊗su(3)c⊗o(1,3) ls rather than su(6) sf ⊗su(3)c⊗o(3) l . The nucleon and ∆ spectra below ∼2500 MeV are complete up to only 5 'missing' resonances. The three O(4) poles are distributed over two distinct Fock spaces of opposite vacuum parities thus defining the energy scale of the chiral phase transition for baryons. Within this new symmetry scenario, the covariant description of the RS baryon clusters is straightforward and their averaged masses are fitted by a Balmer-series like formula emerging from a simple quark-diquark model in the O(4) basis with Coulomb potential and a four-dimensional rigid rotator.

2024

Evidence of secular dynamical evolution for detached active binary orbits are presented. First order decreasing rates of orbital angular momentum (OAM), systemic mass ($M=M_{1}+M_{2}$) and orbital period of detached active binaries have been determined as dotJ/J=−3.48times10−10\dot J/J = -3.48 \times 10^{-10}dotJ/J=−3.48times10−10yr$^{-1}$, dotM/M=−1.30times10−10\dot M/M = -1.30 \times 10^{-10}dotM/M=−1.30times10−10yr$^{-1}$ and dotP/P=−3.96times10−10\dot P/P = -3.96\times 10^{-10}dotP/P=−3.96times10−10yr$^{-1}$ from the kinematical ages of 62 field detached systems. The ratio of dlogJ/dlogM=2.68d \log J/ d \log M = 2.68dlogJ/dlogM=2.68 implies that either there are mechanisms which amplify AM loss delta=2.68\delta=2.68delta=2.68 times with respect to isotropic AM loss of hypothetical isotropic winds or there exist external causes contributing AM loss in order to produce this mean rate of decrease for orbital periods. Various decreasing rates of OAM ($d \log J / dt$) and systemic mass ($d \log M/ dt$) determine various speeds of dynamical evolutions towards a contact configuration. According to average dynamical evolution with delta=2.68\delta = 2.68delta=2.68, the fract...

2024, Nonlinear Spectroscopy