Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Intrinsic optical bistability of thin films of linear molecular
  aggregates: The two-exciton approximation   We generalize our recent work on the optical bistability of thin films of
molecular aggregates [J. Chem. Phys. 127, 164705 (2007); arXiv:0707.1264v1
[cond-mat.dis-nn]] by accounting for the optical transitions from the
one-exciton manifold to the two-exciton manifold as well as the exciton-exciton
annihilation of the two-exciton states via a high-lying molecular vibronic
term. We also include the relaxation from the vibronic level back to both the
one-exciton manifold and the ground state. By selecting the dominant optical
transitions between the ground state, the one-exciton manifold, and the
two-exciton manifold, we reduce the problem to four levels, enabling us to
describe the nonlinear optical response of the film. The one- and two-exciton
states are obtained by diagonalizing a Frenkel Hamiltonian with an uncorrelated
on-site (diagonal) disorder. The optical dynamics is described by means of the
density matrix equations coupled to the electromagnetic field in the film. We
show that the one-to-two exciton transitions followed by a fast exciton-exciton
annihilation promote the occurrence of bistability and reduce the switching
intensity. We provide estimates of pertinent parameters for actual materials
and conclude that the effect can be realized.

1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an