Numerical coupled Liouville approach: dependence of population differences between excited and ground states on field intensity and size of molecular aggregates

In our previous paper, we developed a novel numerical calculation method of quantum dynamics for linear molecular aggregates and investigated the population differences between excited and ground states for dimer models under intense external electric fields. The population and polarizability spectra for dimer models exhibited an abrupt change, like the phase-transition behavior for the applied field intensities. In this Letter we investigate dependences of the population differences on the applied field intensity and size of the molecular aggregates. Plural abrupt changes are found to appear for the intermediate-size aggregates.