Influences of different environmental factors to 2D non-linear spectra of bio-molecular aggregates

In this paper, we investigate the influences of different environmental factors to rephasing spectra of 2D, third-order, non-linear (2D3ONL), photon echo signals for bio-molecular aggregates by using an exact numerical dynamics approach-the quasi-adiabatic propagator path integral (QUAPI) method. It is shown that the increase of temperature and coupling strength between the system and its environment results in not only the inhomogeneous but also the homogeneous broadening of the 2D3ONL rephasing spectra of photon echo signals. However, it is interested that the increase of dynamical memory times, namely, the increase of the non-Markovian effects will mainly lead to the homogeneous broadening of the spectra. The evolutions of the 2D3ONL rephasing spectra with population times are also investigated.