Physical Chemistry Seminar: Spin-Entangled Excitons from Singlet Fission
Professor Joel David Eaves, Department of Chemistry University of Colorado at Boulder Colorado, USA
Zoom: https://tau-ac-il.zoom.us/j/86298492303
The Institute of Advanced Studies IAS Distinguished Scholars
Abstract:
The uncertainty of a system’s wavefunction is a major source of noise in quantum computing. In this talk, I will discuss how singlet fission—a rare photophysical process that splits one exciton into two—can be repurposed as a quantum resource at temperatures far higher than those achievable through passive cooling, as in superconducting circuits. Rather than cooling into the ground state, singlet fission prepares a spin-polarized excited state that is both addressable and readable via magnetic resonance.
By analyzing a model Hamiltonian, I will show how molecular symmetry can be exploited to impose optimal selection rules, enabling precise state preparation. I will also demonstrate how entanglement between spin excitons manifests in time-resolved electron paramagnetic resonance (EPR) spectra in molecular dimers and crystals. Finally, I will describe how to design molecules that employ clock transitions—a technique used to stabilize frequencies in atomic clocks—to extend spin exciton coherence times in singlet fission systems.
The results motivate the development of new theoretical and computational models that can model realistic noise, both from the measurement and detection apparatus (extrinsic), and from the quantum and thermal fluctuations of the system (intrinsic). My two tutorial talks the following week are based on the methods we have developed to model extrinsic and intrinsic noise in multilevel quantum systems.
