相关论文: Excitation of an Atom by Twisted Photons
We show that the twisted photon states, or photon states with large ($> \hbar$) angular momentum projection ($m_\gamma$) in the direction of motion, can photoexcite atomic levels for a hydrogen-like atom that are novel and distinct and are…
We analyze atomic photoexcitation into the discrete states by twisted photons, or photons carrying extra orbital angular momentum along their direction of propagation. From the angular momentum and parity considerations, we are able to…
We calculate transition amplitudes and cross sections for excitation of hydrogen-like atoms by the twisted photon states, or photon states with angular momentum projection on the direction of propagation exceeding $\hbar$. If the target…
We investigate the twisted state of an atom and the possible effect of such a state on the properties of the photons emitted as a result of an electron transition in that atom. We first propose a framework for describing the twisted atomic…
We develop a simple model and propose a scheme that allows the production of twisted atoms in free space using the absorption of twisted photons by a bound electron. We show that in the inelastic collision of a photon and an atom, the…
We consider physical processes caused by the twisted photons for a wide range of energy scales, from optical (eV) to nuclear (MeV) to high-energy gamma-rays (TeV). We demonstrate that in order to satisfy angular momentum conservation,…
The transition probability for the emission of a Bessel photon by an atomic system is calculated within first order perturbation theory. We derive a closed expression for the electromagnetic potentials beyond the paraxial approximation that…
We discuss novel features of twisted-light absorption both by hydrogen-like atoms and by micro-particles. First, we extend the treatment of atomic photoexcitation by twisted photons to include atomic recoil, derive generalized quantum…
Photons carrying non-zero orbital angular momentum (twisted photons) are well-known in optics. Recently, it was suggested to use Compton backscattering to boost optical twisted photons to high energies. Twisted electrons in the intermediate…
The explicit expression for the probability of absorption of a twisted photon by an atomic nucleus has been obtained. It is shown that photoabsorption obeys the selection rule $j\geqslant|m_\gamma|$, where $j$ is the multipolarity of the…
Photoexcitation of planar Wannier excitons by twisted photons in thin semiconductor films is investigated. The explicit general formulas for transition probabilities between exciton states are derived. The selection rules for the projection…
The radiation of twisted photons by charged particles traversing a cholesteric plate is studied in the framework of quantum electrodynamics in an anisotropic inhomogeneous dispersive medium. The complete set of solutions to the Maxwell…
The theory of radiation of twisted photons in elliptical multifrequency undulators is developed. It is shown that helical multifrequency undulators can be employed as a bright and versatile source of photons in the states that are…
The importance of production 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…
The hard X-ray twisted photons and relativistic massive particles with orbital angular momentum -- vortex electrons, muons, protons, etc. -- have many potential applications in high-energy and nuclear physics. However, such states can be…
"Twisted particles" refer to non-plane-wave states of photons, electrons, hadrons, or any other particle which carry non-zero, adjustable orbital angular momentum with respect to their average propagation direction. Twisted photons and…
The explicit expressions for the average number of twisted photons radiated by a charged particle in an elliptical undulator in the classical approximation as well as in the approach accounting for the quantum recoil are obtained. It is…
Usually, photons are described by plane waves with a definite 4-momentum. In addition to plane-wave photons, "twisted photons" have recently entered the field of modern laser optics; these are coherent superpositions of plane waves with a…
Inter-band photo-excitation of electron states with the twisted photons in GaAs, a direct band-gap bulk semiconductor, is considered theoretically. Assuming linearity of the quantum transition amplitudes and applying Wigner-Eckart theorem,…
The relatively new atomic form factor for twisted (vortex) beams, which carry orbital angular momentum (OAM), is considered and compared to the conventional atomic form factor for plane wave beams that carry only spin angular momentum…