Secular vs. Non-secular Redfield Dynamics and Fano Coherences in Incoherent Excitation: An Experimental Proposal

Two different Master Equation approaches have been formally derived to address the dynamics of open quantum systems interacting with a thermal environment (such as sunlight). They have led to two different physical results: non-secular equations that show noise-induced (Fano) coherences and secular equations that do not. An experimental test for the appearance of non-secular terms is proposed using Ca atoms in magnetic fields excited by broadband incoherent radiation. Significantly different patterns of fluorescence are predicted, allowing for a clear test for the validity of the secular and non-secular approach and for the observation of Fano coherences.