Strong Orbital Polarization in a Cobaltate-Titanate Oxide Heterostructure.

Author(s) Lee, S.; Lee, A.Taekyung; Georgescu, A.B.; Fabbris, G.; Han, M.G.; Zhu, Y.; Freeland, J.W.; Disa, A.S.; Jia, Y.; Dean, M.P.M.; Walker, F.J.; Ismail-Beigi, S.; Ahn, C.H.
Journal Phys Rev Lett
Date Published 2019 Sep 13

Through a combination of experimental measurements and theoretical modeling, we describe a strongly orbital-polarized insulating ground state in an (LaTiO_{3})_{2}/(LaCoO_{3})_{2} oxide heterostructure. X-ray absorption spectra and ab initio calculations show that an electron is transferred from the titanate to the cobaltate layers. The charge transfer, accompanied by a large octahedral distortion, induces a substantial orbital polarization in the cobaltate layer of a size unattainable via epitaxial strain alone. The asymmetry between in-plane and out-of-plane orbital occupancies in the high-spin cobaltate layer is predicted by theory and observed through x-ray linear dichroism experiments. Manipulating orbital configurations using interfacial coupling within heterostructures promises exciting ground-state engineering for realizing new emergent electronic phases in metal oxide superlattices.

DOI 10.1103/PhysRevLett.123.117201
ISSN 1079-7114
Citation Phys Rev Lett. 2019;123(11):117201.

Related Applications, Forms & Industries