Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 72: Poster Session: Correlated Electrons

TT 72.72: Poster

Mittwoch, 14. März 2018, 15:00–19:00, Poster B

Investigating the charge transfer in LaVO₃/SrTiO₃ heterostructures by photoemission spectroscopy — •Martin Stübinger¹, Judith Gabel¹, Philipp Gagel¹, Christoph Schlueter², Tien-Lin Lee², Michael Sing¹, and Ralph Claessen¹ — ¹Physikalisches Institut and Röntgen Center for Complex Material Systems (RCCM), Universität Würzburg, Germany — ²Diamond Light Source Ltd., Didcot, Oxfordshire OX11 0DE, United Kingdom

Akin to the well known oxide heterostructure LaAlO₃/SrTiO₃ (LAO/STO) a conducting interface is found also between the strongly correlated, polar Mott insulator LaVO₃ (LVO) and the non-polar band insulator STO. A possible mechanism for this behavior is an electron transfer to the interface caused by the polar discontinuity. Since in LVO/STO the transition metals Ti as well as V can have different oxidation states, they both may act as hosts for the transferred electrons. In particular, a charge transfer to V would lead to a band-filling controlled Mott insulator-to-metal transition. By means of photoemission spectroscopy with synchrotron radiation we investigate the valence band structure of LVO/STO and the band alignment at the interface. In accordance with resonant photoemission at the V-L and the Ti-L edge we arrive at the conclusion that it is energetically more favorable for transferred electrons to occupy Ti than V sites. Therefore, a Mott insulator-to-metal transition is not observed in LVO.