Orbital reconstruction at the LAO/STO interface investigated by x-ray spectroscopy

@inproceedings{ ISI:000285829500010,
Author = {Ghiringhelli, G. and Sala, Moretti M. and Cezar, J. C. and Brookes, N.
   B. and De Luca, G. M. and Salluzzo, M.},
Editor = {{Drouhin, HJM and Wegrowe, JE and Razeghi, M}},
Title = {{Orbital reconstruction at the LAO/STO interface investigated by x-ray
   spectroscopy}},
Booktitle = {{SPINTRONICS III}},
Series = {{Proceedings of SPIE}},
Year = {{2010}},
Volume = {{7760}},
Note = {{Conference on Spintronics III, San Diego, CA, AUG 01-04, 2010}},
Organization = {{SPIE}},
Abstract = {{The appearance of high mobility electrons at the LaAlO3/SrTiO3 (LAO/STO)
   interface has raised strong interest in the material science community
   and a lively debate on the origin of the phenomenon. In particular, in
   view of the large band gaps of the two bulk single crystals constituting
   this heterostructure, the realization of a conducting system was totally
   unexpected. A possible explanation is an electronic reconstruction of
   the interface, realizing a transfer of electrons from the LaAlO3 surface
   to SrTiO3 near the interface, thereby avoiding the polarization
   catastrophe associated with the alternating polar layers of the LaAlO3
   film. The predictions of theoretical models based on this idea are quite
   peculiar and need to be verified by specific experiments able to address
   the electronic properties of the LAO/STO buried interface. Here, by
   using x-ray spectroscopy techniques, we show that the appearance of an
   electron system is correlated to the removal of the degeneracy of the
   titanium 3d states, and doped electrons appear in a band preferentially
   created by the hybridization between 3d(xy) states of titanium and
   oxygen 2p(x,y) states. This splitting is consistent with an ordering of
   the Ti 3d(xy) orbital belonging to the TiO6 octahedra close to the
   interface, as theoretically proposed. However, the valence of titanium
   ions remains prevalently 4+, therefore other mechanisms should be also
   considered for the stabilization of the system.}},
Publisher = {{SPIE-INT SOC OPTICAL ENGINEERING}},
Address = {{1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA}},
Type = {{Proceedings Paper}},
Language = {{English}},
Affiliation = {{Salluzzo, M (Corresponding Author), CNR SPIN, Complesso MonteSantangelo Via Cinthia, I-80126 Naples, Italy.
   Ghiringhelli, G.; De Luca, G. M.; Salluzzo, M., CNR SPIN, Complesso MonteSantangelo Via Cinthia, I-80126 Naples, Italy.
   Ghiringhelli, G.; Sala, Moretti M., Politecn Milan, Dipartimento Fis, I-20133 Milan, Italy.
   Cezar, J. C.; Brookes, N. B., European Synchrotron Radiat Facil, F-38043 Grenoble, France.}},
DOI = {{10.1117/12.861465}},
Article-Number = {{77600V}},
ISSN = {{0277-786X}},
EISSN = {{1996-756X}},
ISBN = {{978-0-8194-8256-3}},
Keywords = {{transition metal oxides; interfaces; X-ray spectroscopies; LAO; STO}},
Keywords-Plus = {{SUPERCONDUCTIVITY}},
Research-Areas = {{Optics; Physics}},
Web-of-Science-Categories  = {{Optics; Physics, Applied}},
Author-Email = {{salluzzo@na.infn.it}},
ResearcherID-Numbers = {{Criginski Cezar, Julio/B-2731-2008
   Cezar, Julio Criginski/D-5039-2012
   salluzzo, marco/C-5919-2009
   Moretti, Marco/AAF-9255-2019
   Sala, Marco Moretti/H-1034-2014
   Brookes, Nicholas B/C-6718-2019
   Ghiringhelli, Giacomo/D-1159-2014}},
ORCID-Numbers = {{Cezar, Julio Criginski/0000-0002-7904-6874
   salluzzo, marco/0000-0001-8372-6963
   Moretti, Marco/0000-0002-9744-9976
   Sala, Marco Moretti/0000-0002-9744-9976
   Brookes, Nicholas B/0000-0002-1342-9530
   Ghiringhelli, Giacomo/0000-0003-0867-7748}},
Number-of-Cited-References = {{20}},
Times-Cited = {{0}},
Usage-Count-Last-180-days = {{0}},
Usage-Count-Since-2013 = {{15}},
Doc-Delivery-Number = {{BSU57}},
Unique-ID = {{ISI:000285829500010}},
DA = {{2020-12-22}},
}