An analysis of models for resonant transer of excitation using quantum electrodynamics

Polarisation analysis of bimolecular excitations mediated by energy transfer: A common theoretical framework for fluorescence migration and sequential Raman scattering

“…Such a description of molecular interactions in terms of virtual photons has found extensive applications in other areas of chemical physics. It has, for example, a pivotal role in the description of chiroptical behaviour associated with intermolecular interactions, as in induced circular dichroism [30][31][32], and it has recently enjoyed extensive application in the theory of intermolecular energy transfer per se [20][21][22][23][24][25] -areas in which Craig and Thirunamachandran have made a number of important contributions. Such considerations here form the basis for a common representation of bimolecular probability amplitudes in terms of the photophysical interactions of the individual molecules A and B, as will be detailed in Sections 4 and 5.…”

“…When the intermolecular distance R is less than the reduced wavelength ~ = A/2'rr (where A is the wavelength corresponding to the energy being transferred) then the transfer is commonly termed a non-radiative or radiationless process and treated as a longitudinal (Coulombic) interaction [14]; alternatively it may be understood to be mediated by virtual photon coupling [15][16][17][18][19][20][21][22][23][24]. From either viewpoint, although it may occur at some interval after initial molecular photoexcitation, each individual transfer of energy is essentially instantaneous, subject to the obvious constraint of causality.…”

Quantum electrodynamics of bimolecular multiphoton processes in the condensed phase

“…In its QED formulation, this emerges as a second-order perturbational process mediated by intermolecular propagation of a virtual photon [8][9][10][11][12][13][14]. The advantage of such a quantum electrodynamical treatment is that it extends the traditional F~Srster theory of short-range (near-zone) dipole-dipole radiationless transfer to arbitrary A-B separations R, thus establishing a continuous connection with long-range (far-zone) radiative transfer.…”

“…Following the extensive analysis of the energy transfer between a pair of molecules in vacuum [8][9][10][11][12][13][14], the medium-induced modifications of the process have also been considered recently [17]. The formalism developed [17] will now be extended to higher-order bimolecular processes that involve real incoming and outgoing photons in addition to the virtual ones.…”

“…For example, two species (A and B) initially in their ground electronic states can together be promoted to by the incident photon annihilated at A (B) is transferred to another molecule B (A) through a virtual photon [1][2][3][4][5][6][7]. Virtual photon coupling is a common feature of all bimolecular photophysical processes, other examples being resonance intermolecular transfer of excitation energy [8][9][10][11][12][13][14], bimolecular Raman scattering [15], bimolecular three-photon absorption [16], etc. Within such a classification, resonance energy transfer,…”