Field Of Magnetic Monopole Research Articles

Creation of Dirac Monopoles in Spinor Bose-Einstein Condensates

We demonstrate theoretically that, by using external magnetic fields, one can imprint pointlike topological defects on the spin texture of a dilute Bose-Einstein condensate. The symmetries of the condensate order parameter render this topological defect to be accompanied with a vortex filament corresponding to the Dirac string of a magnetic monopole. The vorticity in the condensate coincides with the magnetic field of a magnetic monopole, providing an ideal analogue to the monopole studied by Dirac.

NUCLEAR REACTIONS IN THE MAGNETIC MONOPOLE FIELD

The D + D → 4 He reaction can be one of the methods to count the magnetic monopole. In order to prove this, the mechanism of bound state of nucleons and monopole system is clarified. We calculated bound state of nucleon-monopole system by using the Jacobi-coordinate bases antisymmetrized molecular dynamics (or JAMD) method. This calculation is done to show the efficiency of JAMD as a first step of main subject. The binding energy of neutron and proton in the magnetic monopole field is calculated. Our results are compared with those of analytical solution.

Some Comments on Quantum Magnetic Monopoles

In this paper we intend to present some path-integral studies in the problem of confinement in the presence of fermionic and scalar magnetic monopole fields through: 1. A Wilson Loop Path-Integral Evaluation associated to an effective second-quantized electromagnetic field generated by chiral abelian point-like monopole magnetic field current. 2. A Path-Integral Bosonization analysis of Quarks fields interacting with Kalb-Ramond fields considered as an effective Disorder Field Theory of a Q.C.D. vacuum of heavier monopoles. 3. Improvements on the Wilson Loops evaluations in the well-known ADHM Antonov-Ebert model for Cooper pairs of point-like fermionic magnetic monopoles.

Character of the magnetic monopole field

Based upon the Helmholtz decomposition theorem this paper shows that the field of a stationary magnetic monopole, assuming it exists, cannot be represented by a vector potential. Persisting to use vector potential in monopole representation violates fundamentals of mathematics. The importance of this finding is that the vector potential representation was crucial to the original prediction of the quantised value for a magnetic charge.

Magnetic monopole loops supported by a meron pair as the quark confiner

We give an analytical solution representing circular magnetic monopole loops joining a pair of merons in the four-dimensional Euclidean SU(2) Yang-Mills theory. This is achieved by solving the differential equation for the adjoint color (magnetic monopole) field in the two-meron background field within the recently developed reformulation of the Yang-Mills theory. Our analytical solution corresponds to the numerical solution found by Montero and Negele on a lattice. This result strongly suggests that a meron pair is the most relevant quark confiner in the original Yang-Mills theory, as Callan, Dashen, and Gross suggested long ago.

The example of effective plasma acceleration in a magnetosphere

The problem of effective transform of Poynting flux energy into the kinetic energy of relativistic plasma outflow in a magnetosphere is considered. In this article we present an example of such acceleration. In order to perform it, we use the approach of ideal axisymmetric magnetohydrodynamics (MHD). For highly magnetized plasma outflow we show that a linear growth of Lorentz factor with a cylindrical distance from the rotational axis is a general result for any field configuration in the sub-magnetosonic flow. In the far region the full magnetohydrodynamics problem for one-dimensional flow is considered. It turns out that the effective plasma outflow acceleration is possible in the paraboloidal magnetic field. It is shown that such an acceleration is due to the drift of charged particles in the crossed electric and magnetic field. The clear explanation of the absence of acceleration in the monopole magnetic field if given.

Hamiltonian reduction and supersymmetric mechanics with Dirac monopole

We apply the technique of Hamiltonian reduction for the construction of three-dimensional $\mathcal{N}=4$ supersymmetric mechanics specified by the presence of a Dirac monopole. For this purpose we take the conventional $\mathcal{N}=4$ supersymmetric mechanics on the four-dimensional conformally-flat spaces and perform its Hamiltonian reduction to three-dimensional system. We formulate the final system in the canonical coordinates, and present, in these terms, the explicit expressions of the Hamiltonian and supercharges. We show that, besides a magnetic monopole field, the resulting system is specified by the presence of a spin-orbit coupling term. A comparision with previous work is also carried out.

Magnetic monopoles in quantum adiabatic dynamics and the immersion property of the control manifold

It is well known that the Berry phase of a cyclic adiabatic dynamical system appears formally as the flux of a magnetic field in the control parameter manifold. In this electromagnetic picture a level crossing appears as a Dirac magnetic monopole in this manifold. We make an extensive study of the magnetic monopole model of eigenvalue crossings. We show that the properties of the monopole magnetic field in the control manifold are determined by the immersion of the control manifold in a space given by the universal classifying theorem of fiber bundles. We give a detailed illustrative study of the simple but instructive case of a two level crossing of a system controlled by a two-dimensional manifold.

Relativistic magnetohydrodynamics winds from rotating neutron stars

We solve for the time-dependent dynamics of axisymmetric, general relativistic magnetohydrodynamic winds from rotating neutron stars. The mass-loss rate as a function of latitude is obtained self-consistently as a solution to the magnetohydrodynamics equations, subject to a finite thermal pressure at the stellar surface. We consider both monopole and dipole magnetic field geometries and we explore the parameter regime extending from low magnetization (low σ0), almost thermally driven winds to high magnetization (high σ0), relativistic Poynting-flux-dominated outflows (σ=B2/4πργc2β2≈σ0/γ∞,β=v/c with ⁠, where ω is the rotation rate, Φ is the open magnetic flux, and is the mass flux). We compute the angular momentum and rotational energy-loss rates as a function of σ0 and compare with analytic expectations from the classical theory of pulsars and magnetized stellar winds. In the case of the monopole, our high-σ0 calculations asymptotically approach the analytic force-free limit. If we define the spindown rate in terms of the open magnetic flux, we similarly reproduce the spindown rate from recent force-free calculations of the aligned dipole. However, even for σ0 as high as ∼20, we find that the location of the Y-type point (rY), which specifies the radius of the last closed field line in the equatorial plane, is not the radius of the Light Cylinder RL=c/ω (R= cylindrical radius), as has previously been assumed in most estimates and force-free calculations. Instead, although the Alfvén radius at intermediate latitudes quickly approaches RL as σ0 exceeds unity, rY remains significantly less than RL. In addition, rY is a weak function of σ0, suggesting that high magnetizations may be required to quantitatively approach the force-free magnetospheric structure, with rY=RL. Because rY < RL, our calculated spindown rates thus exceed the classic ‘vacuum dipole’ rate: equivalently, for a given spindown rate, the corresponding dipole field is smaller than traditionally inferred. In addition, our results suggest a braking index generically less than 3. We discuss the implications of our results for models of rotation-powered pulsars and magnetars, both in their observed states and in their hypothesized rapidly rotating initial states.

The effective acceleration of plasma outflow in the paraboloidal magnetic field

The problem of the efficiency of particle acceleration for a paraboloidal poloidal magnetic field is considered within the approach of steady axisymmetric magnetohydrodynamic (MHD) flow. For the large Michel magnetization parameter σ it is possible to linearize the stream equation near the force-free solution and to solve the problem self-consistently as was done by Beskin, Kuznetsova & Rafikov for a monopole magnetic field. It is shown that, on the fast magnetosonic surface (FMS), the particle Lorentz factor γ does not exceed the standard value σ1/3. On the other hand, in the supersonic region, the Lorentz factor grows with the distance z from the equatorial plane as γ≈ (z/RL)1/2 up to the distance z≈σ2RL, where RL=c/ΩF is the radius of the light cylinder. Thus, the maximal Lorentz factor is γmax≈σ, which corresponds to almost the full conversion of the Poynting energy flux into the particle kinetic one.

Induced magnetic monopole from trapped Λ-type atom

We investigate the spatial motion of the trapped atom with the electromagnetically induced transparency (EIT) configuration where the two Rabi transitions are coupled to two classical light fields respectively with the same detuning. When the internal degrees of freedom can be decoupled adiabatically from the spatial motion of the center of mass via the Born-Oppenheimer approximation, it is demonstrated that the lights of certain profile can provide the atom with an effective field of magnetic monopole, which is the so-called induced gauge field relevant to the Berry's phase. Such an artificial magnetic monopole structure manifests itself in the characterizing energy spectrum.

Monopole fields from vortex sheets reconciling Abelian and center dominance

We describe a new order parameter for the confinement-deconfinement transition in lattice SU(2) Yang-Mills theory. It is expressed in terms of magnetic monopole field correlators represented as sums over sheets of center vortices. Our construction establishes a link between “abelian” and “center dominance”. It avoids an inconsistency in the treatment of small scales present in earlier definitions of monopole fields by respecting Dirac's quantization condition for magnetic fluxes.

Spectrum of Schrödinger field in a noncommutative magnetic monopole

The energy spectrum of a nonrelativistic particle on a noncommutative sphere in the presence of a magnetic monopole field is calculated. The system is treated in the field theory language, in which the one-particle sector of a charged Schrödinger field coupled to a noncommutative U(1) gauge field is identified. It is shown that the Hamiltonian is essentially the angular momentum squared of the particle, but with a nontrivial scaling factor appearing, in agreement with the first-quantized canonical treatment of the problem. Monopole quantization is recovered and identified as the quantization of a commutative Seiberg–Witten mapped monopole field.

Direct numerical simulations of the Blandford-Znajek effect

The time-dependent general relativistic equations of degenerate electrodynamics are solved numerically in order to study the mechanism of the electromagnetic extraction of the rotational energy of black holes. We performed a series of 2D runs for black holes with specific angular momentum, a, from 0.1 to 0.9 and for a monopole magnetic field assuming axisymmetry. In the inner region of the wind, the solution quickly settles to a steady state with an outgoing Poynting flux. In all cases the angular velocity of the magnetic field lines is almost half the angular velocity of the black hole. Thus, at least for the configuration considered, the Blandford–Znajek mechanism operates near its maximum power output.

Free conical dynamics: charge-monopole as a particle with spin, anyon and nonlinear fermion-monopole supersymmetry

We discuss the origin of the effectively free dynamics of the charge in the magnetic monopole field to apply it for finding the alternative treatment of the charge-monopole as a particle with spin, for tracing out the relation of the charge-monopole to the free relativistic anyon and for clarifying the nature of the non-standard nonlinear supersymmetry of the fermion-monopole system.

Quantization and spectral geometry of a rigid body in a magnetic monopole field

A rigid body with a fixed point in an effective homogeneous magnetic field, which can be thought of as a magnetic monopole, is studied in the framework of geometric quantization. It turns out that there are two cases. The non-degenerate case, with SO(3) as configuration space, presents no obstruction to quantization, but has two non-equivalent quantizations. The degenerate case, which reduces to the study of a single particle in a constant magnetic field on S 2 , is quantizable if it satisfies the Dirac quantization condition. In the non-degenerate case, using techniques from harmonic analysis, the Schrödinger equation for the two quantizations is explicitly solved for a spherical top, and for a symmetric top, in the case that the direction defined by the total magnetic term is along the symmetry axis. The same techniques plus Riemannian submersion theory are applied in the degenerate case to solve the Schrödinger equation

The ABCs of Magnetic Monopole Dynamics

We revisit the explicit solution of Newton's equation of motion (mass times acceleration equals force) for a (pointlike, massive) magnetic monopole moving in the Coulomb field of a (fixed, pointlike) electric charge or, equivalently, of a (pointlike, massive) electric charge moving in the magnetic field of a (fixed) magnetic monopole.

Quantum phase of an electric dipole moving in a magnetic dipole field

It is shown that a neutral particle with an electric dipole moment acquires a quantum phase of Aharonov-Bohm type which is induced by a magnetic dipole field, in addition to the He-McKellar-Wilkens phase which requires a magnetic monopole field. Therefore this phase is measurable in principle. This phase is related to the Casella phase in the sense of the electromagnetic duality.

The Bardeen model as a nonlinear magnetic monopole

The Bardeen model — the first regular black hole model in General Relativity — is reinterpreted as the gravitational field of a nonlinear magnetic monopole, i.e., as a magnetic solution to Einstein equations coupled to a nonlinear electrodynamics.

Genuine dyons in Born-Infeld electrodynamics

A study of magnetic monopoles in the original version of Born-Infeld (BI) electrodynamics is performed. It then is realized that interesting new physics emerges and it includes exotic behavior of the radial electric monopole field such as its regularity as $\stackrel{\ensuremath{\rightarrow}}{r}0$ and its changing behavior with the absence or presence of the radial magnetic monopole field. This last point has been interpreted as the manifestation of the existence of pointlike dyons in Abelian BI theory. Two pieces of clear evidence in favor of this dyon interpretation are provided. It is also demonstrated that despite these unique features having no analogue in standard Maxwell theory, the cherished Dirac quantization condition remains unchanged. Lastly, comments are given concerning that dyons found here in the original version of BI electrodynamics should be distinguished from the ones with the same name, or BIons, being studied in the recent literature on D-brane physics.