Dynamical Simulations of Polaron Spin-Filtering and Rectification in an Organic Magnetic–Nonmagnetic Co-oligomer: The Interfacial Effect

The interfacial effect on the dynamical properties of spin-dependent polarons in an organic magnetic/nonmagnetic co-oligomer is investigated by using a tight-binding model coupled with a nonadiabatic dynamic method. It is found that the dynamical behaviors of spin-up and spin-down polarons are quite different at the interface. In the presence of an external electric field, polarons with a specific spin (up or down) can get trapped near the magnetic/nonmagnetic interface while the motion of polarons with an opposite spin is not affected, which leads to the phenomenon of polaron spin-filtering. Interestingly, when the electric field is reversely applied, only polarons with opposite spin can pass through the co-oligomer and spin rectification can be observed. The spin-filtering and rectification can be improved by increasing the strength of the spin correlation in the magnetic part of the co-oligomer and they can also be affected by the strength of the interfacial electron–lattice coupling and the electronic transfer integral. These findings are useful for the design of organic-based spin logic devices.