One of the dreams of today’s science is to be capable of harvesting electricity back from dissipated heat. The key to this probably resides in circuits that contain single molecules: instead of being limited to the classical conductance, the thermopower can be enhanced dramatically by the properties of quantum states. But then, what quantum states offer good efficiency? What characteristics are desirable? To these questions, theory often offers contrasting predictions, and experiments have given no proof.
Our measurements, first of their kind, unveil the different contributions of different states, and unveil the importance of electron-vibrational coupling and of spin entropy.
We thus validate theories about what factors impact most crucially the thermoelectric properties, and indicate the synthetic directions to influence the heat to energy conversion in single molecules.
Nature Technology publication - March 2021