Stimulated emission of virtual photons: Energy transfer by light

TL;DR

This paper explores how virtual photon emission can be stimulated by real photons to enable energy transfer processes like ICD, which are normally inactive at low energies, with potential applications in molecular and atomic systems.

Contribution

It introduces the concept of stimulated energy transfer via virtual photons, extending the understanding of ICD mechanisms in the presence of photon fields.

Findings

Stimulated ICD can activate energy transfer at lower excess energies.

Photon presence enhances long-range Coulombic interactions.

Examples demonstrate the potential role of stimulated processes in molecular systems.

Abstract

Energy-transfer processes can be viewed as being due to the emission of a virtual photon. It is demonstrated that the emission of virtual photons and thus of energy transfer is stimulated by the sheer presence of photons. We concentrate here on interatomic/intermolecular Coulombic decay (ICD) where an excited system relaxes by transferring its excess energy to a neighbor ionizing it. ICD is inactive if this excess energy is insufficiently large. However, in the presence of photons, the long-range interaction between the system and its neighbor can utilize the photon field making ICD active. The properties of this stimulated-ICD mechanism are discussed. The concept can be transferred to other scenarios. We discuss collective-ICD where two excited molecules concertedly transfer their excess energy. Also here, the presence of photons can make the process active if the sum of excess energies were insufficient to do so. Examples with typical molecules and atoms are presented to demonstrate that these stimulated processes can play a role.