In all archetypical reported (001)-oriented perovskite heterostructures, it has been deduced that the preferential occupation of two-dimensional electron gases is in-plane dxy state. In sharp contrast to this, the investigated electronic structure of a spinel-perovskite heterostructure γ-Al2O3/SrTiO3 by resonant soft X-ray linear dichroism, demonstrates that the preferential occupation is out-of-plane dxz/dyz states for interfacial electrons. Moreover, the impact of strain further corroborates that this anomalous orbital structure can be linked to the altered crystal field at the interface and symmetry breaking of the interfacial structural units. Our findings provide another interesting route to engineer emergent quantum states with deterministic orbital symmetry.
@article{arxiv.1608.04405,
title = {Anomalous orbital structure in a spinel-perovskite interface $\gamma$-Al$_2$O$_3$/SrTiO$_3$},
author = {Yanwei Cao and Xiaoran Liu and P. Shafer and S. Middey and D. Meyers and M. Kareev and Z. Zhong and J. -W. Kim and P. J. Ryan and E. Arenholz and J. Chakhalian},
journal= {arXiv preprint arXiv:1608.04405},
year = {2016}
}