Magneto-Orbital Coupling At Room Temperature In Superlattices Consisting Of Nonferroic Constituent Layers

We have investigated the magnetic field dependence of the orbital structure of an artificial tricolor superlattice composed of nonferroic insulators, NdMnO3, SrMnO3, and LaMnO3, at room temperature. Surprisingly, an external magnetic field applied at room temperature causes a pronounced orbital polarization change in superlattices with a shortest period and many interfaces, and it had no influence on the orbital configuration of superlattices with thicker constituent layers. The magneto-orbital coupling observed in the superlattices with nonmultiferroic constituents even at room temperature suggest the crucial role of interfaces and interface-induced oxygen octahedral rotation discontinuity. The magneto-orbital coupling and its mechanism are demonstrated by theoretical calculations. Our findings raise possible implications in orbital engineering to control physical properties.