Andrei Afanasev

High-multipole excitations of hydrogen-like atoms by twisted photons near a phase singularity

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 . If the target atom is located at distances of the order of atomic size near the phase singularity in the vortex center, the transition rates into the states with orbital angular momentum become comparable with the rates for electric dipole transitions. It is shown that when the transition rates are normalized to the local photon flux, the resulting cross sections for are singular near the optical vortex center. The relation to the quantum core concept introduced by Berry and Dennis is discussed.

Contribution of

Lepton mass effects play a decisive role in description of elastic lepton-proton scattering when the beams energy is comparable to the mass of the lepton. The future MUSE experiment, which is devised to solve the Proton Radius Puzzle, is going to cover the corresponding kinematic region for a scattering of muons by a proton target. We anticipate that helicity-flip meson exchanges will make a difference in comparison of elastic electron-proton versus muon-proton scattering in MUSE. In this article, we estimate the

\sigma

sigma

-meson exchange to elastic lepton-proton scattering

meson exchange contribution in the

Experimental verification of position-dependent angular-momentum selection rules for absorption of twisted light by a bound electron

t

Modeling and simulation of InAs/GaAs quantum dot solar cells in SILVACO TCAD

-channel. This contribution, mediated by two-photon coupling of

Tuning up the performance of GaAs-based solar cells by inelastic scattering on quantum dots and doping of AlyGa1-ySb type-II dots and AlxGa1-xAs spacers between dots

sigma

Modification of band alignment at interface of AlyGa1-ySb/AlxGa1-xAs type-II quantum dots by concentrated sunlight in intermediate-band solar cells with separated absorption and depletion regions

, is calculated to be at most

Simulations of properties of quantum dots and high-efficiency GaAs solar cells

sim 0.1 %

Two properties of twisted-light absorption

for muons in the kinematics of MUSE and it is about 3 orders in magnitude larger than for electrons because of the lepton-mass difference.