Journal Article

FZJ-2013-03754

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png LaAlO3 stoichiometry is key to electron liquid formation at LaAlO3/SrTiO3 interfaces

Warusawithana, M. P. (Corresponding author) ; Richter, C. ; Mundy, J. A. ; Roy, P. ; Ludwig, J. ; Paetel, S. ; Heeg, T. ; Pawlicki, A. A. ; Kourkoutis, L. F. ; Zheng, M. ; Lee, M. ; Mulcahy, B. ; Zander, W.FZJ* ; Zhu, Y. ; Schubert, J.FZJ* ; Eckstein, J. N. ; Muller, D. A. ; Hellberg, C. S. ; Mannhart, J. ; Schlom, D. G.

2013
Nature Publishing Group London

This record in other databases:      

Please use a persistent id in citations: http://hdl.handle.net/2128/24482  doi:10.1038/ncomms3351

Abstract: Emergent phenomena, including superconductivity and magnetism, found in the two-dimensional electron liquid (2-DEL) at the interface between the insulators lanthanum aluminate (LaAlO3) and strontium titanate (SrTiO3) distinguish this rich system from conventional 2D electron gases at compound semiconductor interfaces. The origin of this 2-DEL, however, is highly debated, with focus on the role of defects in the SrTiO3, while the LaAlO3 has been assumed perfect. Here we demonstrate, through experiments and first-principle calculations, that the cation stoichiometry of the nominal LaAlO3 layer is key to 2-DEL formation: only Al-rich LaAlO3 results in a 2-DEL. Although extrinsic defects, including oxygen deficiency, are known to render LaAlO3/SrTiO3 samples conducting, our results show that in the absence of such extrinsic defects an interface 2-DEL can form. Its origin is consistent with an intrinsic electronic reconstruction occurring to counteract a polarization catastrophe. This work provides insight for identifying other interfaces where emergent behaviours await discovery.

---

Contributing Institute(s):

1. Halbleiter-Nanoelektronik (PGI-9)
2. Jülich-Aachen Research Alliance - Fundamentals of Future Information Technology (JARA-FIT)

Research Program(s):

1. 421 - Frontiers of charge based Electronics (POF2-421) (POF2-421)

Appears in the scientific report 2013

---

Database coverage:
; ; BIOSIS Previews ; Current Contents - Agriculture, Biology and Environmental Sciences ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection ; Zoological Record

---