Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 27: CE: Poster Session

TT 27.10: Poster

Mittwoch, 24. März 2010, 14:00–18:00, Poster D1

Hard x-ray photoemission spectroscopy on LaAlO₃/LaNiO₃ multilayers — •Patrick Helmecke¹, Götz Berner¹, Michael Sing¹, Johannes Walde¹, Eva Benckiser², Georg Cristiani², Hanns-Ulrich Habermeier², and Ralph Claessen¹ — ¹Experimentelle Physik 4, Universiät Würzburg — ²MPI-FKF Stuttgart

Recently, oxide heterostructures attract attention due to novel physical properties at their interfaces. A case in point is the 1/1 heterostructure LaO-NiO₂-LaO-AlO₂ (LAO/LNO/LAO). For that it has recently been predicted that by substrate-imposed strain one of the two conductions bands can be pushed up such that it is almost completely depleted. Inclusion of electron-electron interactions would shift this band further up, inducing a single Fermi surface (FS) sheet which resembles that of the high-T_c superconducting cuprates with prospects to carry high-temperature superconductivity as well [1].

While experimentally it is not yet possible to fabricate the 1/1 heterostructure with the required precision, we analyzed multilayers with layer thicknesses between 2uc and 4uc by means of hard-x-ray photoelectron spectroscopy to access the buried LNO layers. Interestingly, from Ni core-level spectra we have found evidence for a charge-transfer in the 2uc/2uc sample to Ni which might have an important impact on the FS topology and hence the idea to artificially design a cuprate-like FS.

[1] P. Hansmann, X. Yang, A. Toschi, G. Khaliullin, O. K. Andersen, and K. Held, Phys. Rev. Lett. 103, 016401 (2009).