"Inelastic x-ray scattering in heterostructures: electronic excitations in LaAlO3/SrTiO3"

Kari O Ruotsalainen: Christoph J Sahle, Tobias Ritschel, Jochen Geck, Masayuki Hosoda, Christopher Bell, Yasuyuki Hikita, Harold Y Hwang, Tim T Fister, Robert A Gordon, Keijo Hämäläinen, Mikko Hakala and Simo Huotari; Journal of Physics: Condensed Matter , 07/29/15.

Additional Authors: Christoph J Sahle, Tobias Ritschel, Jochen Geck, Masayuki Hosoda, Christopher Bell, Yasuyuki Hikita, Harold Y Hwang, Tim T Fister, Robert A Gordon, Keijo Hämäläinen, Mikko Hakala and Simo Huotari

Abstract:

We present an investigation of the valence-electron excitation spectra including the collective plasmon modes of SrTiO3, LaAlO3 and their heterostructures with non-resonant inelastic x-ray scattering. We analyse the spectra using calculations based on first principles and atomic multiplet models. We demonstrate the feasibility of performing valence IXS experiments in a total reflection geometry. Surprisingly, we find that the plasmon, interband and semicore excitations in multilayers are well described as a superposition of bulk-compound spectra even in a superstructure composing of layers of only one atomic layer thickness.