Angular momentum of radiation from a charge in circular and spiral motion

The general formula for probability to record a twisted photon produced by a charged particle moving in an inhomogeneous isotropic dispersive medium is derived. The explicit formulas for probability to record a twisted photon are obtained for the radiation of a charged particle traversing a dielectric plate or an ideally conducting foil. It is shown that, in the case when the charged particle moves along the detector axis, all the radiated twisted photons possess a zero projection of the total angular momentum and the probability of their radiation is independent of the photon helicity. The radiation produced by helically microbunched beams of charged particles is also considered. The fulfillment of the strong addition rule for the projection of the total angular momentum of radiated twisted photons is demonstrated. Thus the helical beams allow one to generate coherent transition and Vavilov-Cherenkov radiations with large projections of the total angular momentum. The radiation produced by charged particles in a helical medium is studied. Typical examples of such a medium are metallic spirals and cholesteric liquid crystals. It is shown that the radiation of a charged particle moving along the helical axis of such a medium is a pure source of twisted photons. *

show abstract

“…where the sign "±" agrees with the choice of the sign in (87). The contribution of transition radiation to (86) reaches a maximum at…”

Section: Dielectric Platesupporting

confidence: 66%

“…The fact that probability (86) is concentrated at m = 0 is a consequence of the general rule [82]. This property holds for any current density symmetric under the rotations around the detector axis.…”

Section: Dielectric Platementioning

confidence: 92%

Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive medium

2019

View full text Add to dashboard Cite

show abstract

“…This area is usually referred to as a wave zone. We have shown that the flux of angular momentum in the wave zone is proportional to the vector product of the radius vector of the observation point by the Poynting vector (Eqs ( 8) and (12). Since the angular momentum depends significantly on the choice of coordinate system, two limiting cases can be distinguished: i) the distance between the charge and the origin is comparable to the distance between the charge and the point of observation, and ii) the distance between the charge and the origin is much less than the distance between the charge and the point of observation.…”

Section: Discussionmentioning

confidence: 99%

“…Radiation in the X-ray range carrying the angular momentum was obtained by converting an x-ray beam [8] and by use of a helical undulator [9]. Various schemes of twisted photon beam production in undulators [10][11][12] and free electron lasers [13] have been proposed. Cherenkov radiation and transition radiation emitted by vortex electrons was studied theoretically [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Angular momentum transfered by the field of a moving point charge

Epp,

Guselnikova,

Kamenskaya

2021

Preprint

Self Cite

View full text Add to dashboard Cite

The flux of angular momentum of electromagnetic field of an arbitrarily moving point charge is investigated. General equations are obtained for the transfer of angular momentum at arbitrary distance from the charge, and corresponding equations in the far-field approximation. An explicit expression is obtained for the flux of angular momentum in the wave zone in terms of coordinates, velocity, and acceleration of the charge. The torque is calculated, that would act on an object if it absorbed all the radiation incident on it. It is shown that this torque is proportional to the curl of the stress tensor of the electromagnetic field; in the far field approximation the torque is proportional to the curl of the Poynting vector.

show abstract

“…The recent theoretical [19][20][21] and experimental [22] papers unambiguously show that the photons radiated by electrons in a helical or circular motion are twisted (i.e., have nonzero OAMs). Similar effects takes place for rotating black holes [23,24].…”

mentioning

confidence: 97%

Twisted particles in heavy-ion collisions

Silenko¹,

Zhang²,

Zou³

2021

Proceedings of 40th International Conference on High Energy Physics — PoS(ICHEP2020)

View full text Add to dashboard Cite

The importance of twisted (vortex) particles in heavy-ion collisions is analyzed. Free twisted particles can possess giant intrinsic orbital angular momenta. Twisted particles are spatially localized and can be rather ubiquitous in laboratories and nature. Twisted photons have nonzero effective masses. Charged twisted particles can be recognized by their dynamics, magnetic moments, and specific effects in external fields.

show abstract

Angular momentum of radiation from a charge in circular and spiral motion

Cited by 27 publications

References 17 publications

Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive medium

Probability of radiation of twisted photons in an inhomogeneous isotropic dispersive medium

Angular momentum transfered by the field of a moving point charge

Twisted particles in heavy-ion collisions

Contact Info

Product

Resources

About