Decay of polarization anisotropy ( r ) as a function of magnetic field. In an unaligned solution under no magnetic field, we find that the anisotropy is initially -0.2 and decays to close to 0 within 1 ps (green and blue), indicating the photoexcited state is perpendicular to the probed state after 1 ps (the differences in the V and H polarized experiments at 0 mT demonstrate the setup’s resolution). On application of the 800-mT field, however, photoexciting V polarized (PNR long-axis dipole, orange curve), we find that the anisotropy retains its sign (indicating the photoexcited state is the same orientation as the probed one) whereas when photoexciting H polarized (PNR short-axis dipole, red curve), the anisotropy flips sign, indicating a dipole flip, as in the unpolarized case, with the average converging to the unpolarized system, as expected.
