Giant Optical Polarization Rotation Induced by Spin-Orbit Coupling in Polarons

In this work, published in Physical Review Letters, we demonstrate that the polarization of light is changed dramatically when its energy resonates with the polaron-hopping energy of self-trapped electrons.  In the presence of spin-orbit coupling, the self-trapped hopping electron may reverse its spin producing a large gyrotropic effect, which is observed close to room temperature. The effect is observed in La23Ca13MnO3 thin films and, plausibly, should be present in other manganites.

Since straining this kind of materials can change the polaron concentration, our finding suggests a route to mechanical or electro-mechanical control of the magneto-optical effect, paving  the way to unconventional magnetoelectric effects.

This work has been highlighted with a Synopsis on the Physics website: