Zhaoliang Liao

(Oak Ridge National Lab)

Bandwidth Controlled Correlated Oxide Heterostructures

Oxide heterostructures provide unprecedented opportunities to engineer delicate coupling between spin, orbital, charge and lattice degrees of freedoms. At interface of two dissimilar materials, proximity effect, exchange interaction and possible charge transfer have been demonstrated to give rise to many emergent phenomena [1]. The orbital covalency plays a pivotal role in determining novel properties and functionalities in transition metal oxides. By playing with newly revealed and focused interfacial oxygen octahedral coupling (OOC) in perovskite oxide heterostructures, we demonstrate the capabilities to control bandwidth and thus to induce new and/or engineer existing properties in correlated heterostructures. We have extensively studied the structure-properties correlation in manganite and nickelate heterostructures via STEM, RXR, XAS together with properties characterization and theoretical calculation. Our results illustrated how the spatial variation of bandwidth leads to the long-standing puzzled thickness driven magnetic transition in La2/3Sr1/3MnO3 thin films. I will also summarize our recent results on how to control the bandwidth in both short and long range via normal accepted short range OOC effect in order to manipulate magnetic anisotropy, ferro/antiferromagnetic order and metal-to-insulator transition in correlated heterostructures.