Molecular Control of Spin-Entangled Triplet Excitons from Singlet Fission

This proposal addresses fundamental issues in quantum information science by investigating transformative concepts based on a recently discovered phenomena in organic molecular systems. The ultrafast splitting of one electron-hole pair produced by photon excitation into two electron-hole pairs via a process called singlet fission can result in entangled spin in a pair of excitons. The persistence of the entanglement into the microsecond timescale even at room temperature has been suggested but not studied in detail. The proposed research seeks to understand and control the entanglement through molecular design and the architecture of molecular aggregates. The tuning of interactions between the chromophores on which the pair of spin-1 (triplet) excitons resides will be used to influence the energy level splitting between sublevels. The arrangement of molecules and the introduction of interfaces will be explored for purposes of transporting the excitons and transducing their energy while maintaining entanglement.