For the discussion of the size dependence of the third-order nonlinear susceptibility χ (3) for confined electronic systems, the result of numerical study is given for an exactly soluble model of noninteracting Frenkel excitons in a periodic chain. The case of pump-probe type nonlinear effect is explicitly treated in the long-wavelength approximation, and Im [χ (3) ] is evaluated as a function of chain size N, transfer energy b, and damping constants. For a given value of b(N), there is an enhancement of χ (3) with increasing value of N(b), followed by a saturation behavior. The range of the enhancement is determined by the damping constants. This provides a consistent view of the size and transfer dependence of χ (3) , its saturation behavior, and the previously discussed cancellation problem.
No takes yet. Share an insight, caveat, or question.
Ishihara et al. (1992) studied this question.