Zeeman shift of two-dimensional optical signals of Mg-porphyrin dimers with circularly polarized beams.

Two-dimensional (2D) electronic spectra of Mg-porphyrin dimers with circularly polarized laser pulses are simulated for two molecular geometries. The Zeeman shift of the non-chiral 2D spectra induced by a magnetic field highlights spectral regions that are dominated by exciton states with large total angular momentum, and are particularly sensitive to the geometry. These 2D shifts show much higher sensitivity to the molecular array than the absorption spectrum shifts. For different molecular geometries, only the intensity of the 2D spectrum peaks changes while the form of the Zeeman shifts in the 2D frequency space is modified.