We investigate enhancement of electric multipole excitations of atoms in the vicinity of an object with a nanoscale edge resulted from a large electromagnetic field gradient. We calculate the excitation efficiencies of a Rb atom around a nanoedge and find the excitations are enhanced by several orders of magnitude. The efficiencies with the change in the magnetic quantum number resolved are also examined. Each resolved efficiency shows rotationally symmetric spatial distribution, with continuous modification in shape from the far field to the near field. Furthermore, we estimate photon emission rates accompanied with multipole excitations in alkali (Rb and Cs) atoms and discuss the possibility to observe the enhancement in the multi-pole excitation in cold atoms.We investigate enhancement of electric multipole excitations of atoms in the vicinity of an object with a nanoscale edge resulted from a large electromagnetic field gradient. We calculate the excitation efficiencies of a Rb atom around a nanoedge and find the excitations are enhanced by several orders of magnitude. The efficiencies with the change in the magnetic quantum number resolved are also examined. Each resolved efficiency shows rotationally symmetric spatial distribution, with continuous modification in shape from the far field to the near field. Furthermore, we estimate photon emission rates accompanied with multipole excitations in alkali (Rb and Cs) atoms and discuss the possibility to observe the enhancement in the multi-pole excitation in cold atoms.

Optics ExpressApr 14, 201714 citations

Atomic interference in light fields

B Ya Dubetskiĭ, A. P. Kazantsev, V. P. Chebotaev +1 more

IzSSRMar 1, 19850 citations

Toroidal Transitions in Hydrogenic and Alkali Atoms

Kai Xiang Lee, Vincent Mancois, Kelvin Lim +1 more

In addition to electric and magnetic multipoles, the expansion of current density also yields toroidal terms, a lesser-known family of multipoles. A recent proposal, I. Kuprov $\textit{et al.}$ , Science Adv. 8 abq6751 (2022), explores the possibility of a direct observation of optical toroidal transitions in hydrogen and alkali atoms in the presence of a large magnetic field that decouples the spin and the angular momentum of the electron. However, the difficulty of observing these transitions against the nearby electric dipole (E1) transitions were underestimated because of extra admixture coming from diamagnetic coupling. Here, we revisit the toroidal coupling in atoms, taking diamagnetic contribution into account, and discuss the technical challenges of observing toroidal coupling in atomic physics. We show that toroidal transition should be searched in transitions with low principal quantum numbers. The remaining strong electric-dipole contribution could be removed using an appropriate differential measurement.In addition to electric and magnetic multipoles, the expansion of current density also yields toroidal terms, a lesser-known family of multipoles. A recent proposal, I. Kuprov $\textit{et al.}$, Science Adv. 8 abq6751 (2022), explores the possibility of a direct observation of optical toroidal transitions in hydrogen and alkali atoms in the presence of a large magnetic field that decouples the spin and the angular momentum of the electron. However, the difficulty of observing these transitions against the nearby electric dipole (E1) transitions were underestimated because of extra admixture coming from diamagnetic coupling. Here, we revisit the toroidal coupling in atoms, taking diamagnetic contribution into account, and discuss the technical challenges of observing toroidal coupling in atomic physics. We show that toroidal transition should be searched in transitions with low principal quantum numbers. The remaining strong electric-dipole contribution could be removed using an appropriate differential measurement.

physics.atom-phCross-listedarXiv:2607.19832Jul 23, 20260 citations

Interference effects in quantum transitions

M.I. Podgoretskii, O.A. Khrustalev

Uspekhi Fizicheskih NaukJan 1, 196313 citations

Multiple Nature of Elementary Sources of Radiation—Wide-Angle Interference

Simon Freed, S. I. Weissman

It has been shown possible in wide-angle interference experiments to analyze radiation with respect to its multipole character. The fluorescence from ions of europium in solution consisted of different kinds of radiation in that they possessed different interference properties. From the behavior of the fringe systems, one group of spectral lines was identified as arising from magnetic dipoles while two other groups had their origin in the forced oscillations of electric dipoles. The multipole character of the radiation of a quantum transition was found modified by a change in the microscopic fields about the emitting ions.It has been shown possible in wide-angle interference experiments to analyze radiation with respect to its multipole character. The fluorescence from ions of europium in solution consisted of different kinds of radiation in that they possessed different interference properties. From the behavior of the fringe systems, one group of spectral lines was identified as arising from magnetic dipoles while two other groups had their origin in the forced oscillations of electric dipoles. The multipole character of the radiation of a quantum transition was found modified by a change in the microscopic fields about the emitting ions.

Physical ReviewSep 15, 194158 citations

In addition to electric and magnetic multipoles, the expansion of current density also yields toroidal terms, a lesser-known family of multipoles. A recent proposal, I. Kuprov

\textit{et al.}

, Science Adv. 8 abq6751 (2022), explores the possibility of a direct observation of optical toroidal transitions in hydrogen and alkali atoms in the presence of a large magnetic field that decouples the spin and the angular momentum of the electron. However, the difficulty of observing these transitions against the nearby electric dipole (E1) transitions were underestimated because of extra admixture coming from diamagnetic coupling. Here, we revisit the toroidal coupling in atoms, taking diamagnetic contribution into account, and discuss the technical challenges of observing toroidal coupling in atomic physics. We show that toroidal transition should be searched in transitions with low principal quantum numbers. The remaining strong electric-dipole contribution could be removed using an appropriate differential measurement.