Sindhana Pannir-Sivajothi
(University of California, Berkeley)

The chirality-induced spin selectivity (CISS) effect, where electron transmission through chiral molecules is spin-dependent, has been observed experimentally in several systems. CISS is typically attributed to chirality defined by nuclear geometry. In this talk, I will present a mechanism for generating spin polarization via photoinduced electron transfer in an achiral donor-acceptor complex under circularly polarized light excitation. Here, the chirality arises from the driven electronic degrees of freedom, distinct from that of static nuclear geometry. I will focus on the energetic and symmetry requirements for this spin polarization, demonstrating the effect in a simple model of a metalloporphyrin complex with an axial acceptor ligand using quantum mechanical rate theories and numerical simulations. The resultant spin polarization increases with the spin-orbit coupling strength and is transient, with a lifetime determined by the vibronic coupling.
 

Zoom registartion link:

https://zoom.us/meeting/register/1Q_n5qKWTiyAWoyeH2hvpQ