Probing tailored octahedral modulations in isovalent manganite superlattices with standing-wave-excited angle-resolved photoemission

Tailoring and spatially-confining electronic and ferroic behavior via coherent epitaxy offers a promising avenue towards engineering new functional properties in complex oxide heterostructures [1]. Here we utilize soft x-ray standing-wave photoemission spectroscopy to non-destructively probe depth-dependent electronic structure of isovalent manganite superlattices wherein the electronic and magnetic properties are modulated with depth via O octahedra rotations. Standing-wave-excited spectroscopy of the Mn 2p and O 1s core-levels confirms isovalent nature of the Mn ions in the superlattice and reveals significant depth-dependent variations in the local chemical and electronic environment around the O atoms consistent with rotational modulations of the O octahedra. Momentum-resolved standing-wave spectroscopy reveals modulations in the valence-band dispersion of the strongly-hybridized Mn and O states. \newline [1] E. J. Moon et al., Nature Comm. 5, 5710 (2014).