Figure 2. Probability that the exciton stays on the chromophore it started in represented by the density matrix element .

Below the transition () coherence dies out quickly and the probability reaches its asymptotic value . The peak at is the result of the interference of waves going clock and anti-clockwise along the the circle and meeting again after turning around the structure. The rest of the structure comes from interference of waves scattering back from other chromophores. In the transition point and above coherent beats occur and the probability stays elevated for a very long time (not shown here). These are beats due to genuine quantum coherent superposition states.