Photoexcitation of planar Wannier excitons by twisted photons

TL;DR

This paper derives formulas for exciting planar Wannier excitons with twisted photons, revealing selection rules and potential applications as on-chip twisted photon sources, with implications for impurity-bound states.

Contribution

It provides explicit formulas for transition probabilities and selection rules for exciton photoexcitation by twisted photons in thin semiconductor films.

Findings

Derived general formulas for transition probabilities.

Established selection rules for angular momentum projection.

Discussed applications as on-chip twisted photon sources.

Abstract

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 of the total angular momentum are obtained. As examples, the Coulomb and Rytova-Keldysh electron-hole interaction potentials are considered. The use of planar excitons as a pure on-chip source of twisted photons is discussed. The formulas obtained also describe photoexcitation of states of electrons and holes bound to charged impurities in planar semiconductors.