Theoretical models of energy transfer in two-dimensional molecular assemblies.

An interesting class of Langmuir-Blodgett monolayers, which are called J aggregates or Scheibe aggregates, exhibit energy transfer that is activated through photon absorption and exhibits remarkable properties of fast and nearly lossless transmission. This paper presents theoretical models intended to address the question of energy transfer in two-dimensional molecular assemblies such as Scheibe aggregates. Second-quantized microscopic Hamiltonians are proposed and quantum-mechanical calculations are subsequently performed in several regimes. Numerical simulations illustrate the existence of long lifetime bound states on impurity ions with shallow energy levels. Due to their efficient energy capture these ions play the role of acceptors. A formulation of the problem in a strongly nonlinear regime leads to two other types of less probable but also possible behavior: soliton formation (the Davydov limit) and frequency selection (the Fr\"ohlich limit).