Preferential occupation of interface bands in La2/3Sr1/3MnO3 films as seen via angle-resolved photoemission

We performed in situ angle-resolved photoemission spectroscopy measurements on La2/3Sr1/3MnO3 thin and ultrathin films deposited onto SrTiO3 substrates in order to determine their electronic band structure. We directly identified, in ultrathin films, an enhancement of the occupation of the out-of-plane Mn 3d eg (3z2−r2) band at the expense of the in-plane 3d eg (x2−y2) band. Such a disproportionate change in orbital occupation is interpreted as the origin of the strong depression of the magnetotransport properties at the interface between manganite films and substrates