Hard x-ray photoemission study of LaAlO3/LaVO3 multilayers

Abstract

We have studied the electronic structure of multilayers composed of a band insulator LaAlO${}_3$ (LAO) and a Mott insulator LaVO${}_3$ (LVO) by means of hard x-ray photoemission spectroscopy, which has a probing depth as large as $\sim 60\mathring{A}$. The Mott-Hubbard gap of LVO remained open at the interface, indicating that the interface is insulating unlike the LaTiO${}_3$/SrTiO${}_3$ multilayers. We found that the valence of V in LVO were partially converted from V${}^{3+}$ to V${}^{4+}$ only at the interface on the top side of the LVO layer and that the amount of V${}^{4+}$ increased with LVO layer thickness. We suggest that the electronic reconstruction to eliminate the polarity catastrophe inherent in the polar heterostructure is the origin of the highly asymmetric valence change at the LVO/LAO interfaces.

5 pages, 7 figures

References in corpus (2)

• Bulk screening in core level photoemission from Mott-Hubbard and Charge-Transfer systems
• Photoemission from buried interfaces in SrTiO3/LaTiO3 superlattices

Cited by in corpus (8)

• The Mott insulator LaTiO_3 in heterostructures with SrTiO_3 is metallic
• Modulation Doping of a Mott Quantum Well by a Proximate Polar Discontinuity
• Embedding approach for dynamical mean field theory of strongly correlated heterostructures
• Electronic structure of the SrTiO${}_3$/LaAlO${}_3$ interface revealed by resonant soft x-ray scattering
• Interface reconstruction in V-oxide heterostructures determined by x-ray absorption spectroscopy
• Novel electronic structure induced by a highly strained oxide interface with incommensurate crystal fields
• Enhanced charge-transfer character in the monoclinic phase of Mott-insulator LaVO3 thin film
• Charge correlation in V${}_2$OPO${}_4$ probed by hard x-ray photoemission spectroscopy