title: Spectroscopic evidence for competing reconstructions in polar multilayers LaAlO3/LaVO3/LaAlO3.
abstract: We have studied the valence redistribution of V in LaAlO(3)/LaVO(3)/LaAlO(3) trilayers, which are composed of only polar layers grown on SrTiO3 (001) substrates, by core-level photoemission spectroscopy. We have found that the V valence is intermediate between V3+ and V4+ for thin LaAlO3 cap layers, decreases with increasing cap-layer thickness, and finally recovers the bulk value of V3+ at approximately 10 unit-cell thickness. In order to interpret these results, we propose that the atomic reconstruction of the polar LaAlO3 surface competes with the purely electronic V valence change so that the polar catastrophe is avoided at the cost of minimum energy.
authors: Department of Physics, University of Tokyo, 3-7-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors: M
authors: M
authors: Takizawa
authors: Y
authors: Y
authors: Hotta
authors: T
authors: T
authors: Susaki
authors: Y
authors: Y
authors: Ishida
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authors: Wadati
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authors: Takata
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authors: Horiba
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authors: Matsunami
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authors: S
authors: Shin
authors: M
authors: M
authors: Yabashi
authors: K
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authors: Tamasaku
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authors: Nishino
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authors: Ishikawa
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authors: A
authors: Fujimori
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authors: HY
authors: Hwang