LaAlO 3 stoichiometry is key to electron liquid formation at LaAlO 3/SrTiO 3 interfaces

M. P. Warusawithana; C. Richter; J. A. Mundy; P. Roy; J. Ludwig; S. Paetel; T. Heeg; A. A. Pawlicki; L. F. Kourkoutis; M. Zheng; M. Lee; B. Mulcahy; W. Zander; Ye Zhu; J. Schubert; J. N. Eckstein; D. A. Muller; C. Stephen Hellberg; J. Mannhart; D. G. Schlom

doi:10.1038/ncomms3351

LaAlO 3 stoichiometry is key to electron liquid formation at LaAlO 3/SrTiO 3 interfaces

M. P. Warusawithana, C. Richter, J. A. Mundy, P. Roy, J. Ludwig, S. Paetel, T. Heeg, A. A. Pawlicki, L. F. Kourkoutis, M. Zheng, M. Lee, B. Mulcahy, W. Zander, Ye Zhu, J. Schubert, J. N. Eckstein, D. A. Muller, C. Stephen Hellberg, J. Mannhart, D. G. Schlom

Research output: Journal article publication › Journal article › Academic research › peer-review

181 Citations (Scopus)

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 LaAlO3has been assumed perfect. Here we demonstrate, through experiments and first-principle calculations, that the cation stoichiometry of the nominal LaAlO3layer is key to 2-DEL formation: only Al-rich LaAlO3results in a 2-DEL. Although extrinsic defects, including oxygen deficiency, are known to render LaAlO3/SrTiO3samples 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.

Original language	English
Article number	2351
Journal	Nature Communications
Volume	4
DOIs	https://doi.org/10.1038/ncomms3351
Publication status	Published - 3 Sept 2013
Externally published	Yes

ASJC Scopus subject areas

Chemistry(all)
Biochemistry, Genetics and Molecular Biology(all)
Physics and Astronomy(all)

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10.1038/ncomms3351

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Warusawithana, M. P., 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., Zhu, Y., Schubert, J., Eckstein, J. N., Muller, D. A., Hellberg, C. S., Mannhart, J., & Schlom, D. G. (2013). LaAlO 3 stoichiometry is key to electron liquid formation at LaAlO 3/SrTiO 3 interfaces. Nature Communications, 4, [2351]. https://doi.org/10.1038/ncomms3351

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title = "LaAlO 3 stoichiometry is key to electron liquid formation at LaAlO 3/SrTiO 3 interfaces",

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 LaAlO3has been assumed perfect. Here we demonstrate, through experiments and first-principle calculations, that the cation stoichiometry of the nominal LaAlO3layer is key to 2-DEL formation: only Al-rich LaAlO3results in a 2-DEL. Although extrinsic defects, including oxygen deficiency, are known to render LaAlO3/SrTiO3samples 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.",

author = "Warusawithana, {M. P.} and C. Richter and Mundy, {J. A.} and P. Roy and J. Ludwig and S. Paetel and T. Heeg and Pawlicki, {A. A.} and Kourkoutis, {L. F.} and M. Zheng and M. Lee and B. Mulcahy and W. Zander and Ye Zhu and J. Schubert and Eckstein, {J. N.} and Muller, {D. A.} and Hellberg, {C. Stephen} and J. Mannhart and Schlom, {D. G.}",

year = "2013",

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Warusawithana, MP, Richter, C, Mundy, JA, Roy, P, Ludwig, J, Paetel, S, Heeg, T, Pawlicki, AA, Kourkoutis, LF, Zheng, M, Lee, M, Mulcahy, B, Zander, W, Zhu, Y, Schubert, J, Eckstein, JN, Muller, DA, Hellberg, CS, Mannhart, J & Schlom, DG 2013, 'LaAlO 3 stoichiometry is key to electron liquid formation at LaAlO 3/SrTiO 3 interfaces', Nature Communications, vol. 4, 2351. https://doi.org/10.1038/ncomms3351

TY - JOUR

T1 - LaAlO 3 stoichiometry is key to electron liquid formation at LaAlO 3/SrTiO 3 interfaces

AU - Warusawithana, M. P.

AU - Richter, C.

AU - Mundy, J. A.

AU - Roy, P.

AU - Ludwig, J.

AU - Paetel, S.

AU - Heeg, T.

AU - Pawlicki, A. A.

AU - Kourkoutis, L. F.

AU - Zheng, M.

AU - Lee, M.

AU - Mulcahy, B.

AU - Zander, W.

AU - Zhu, Ye

AU - Schubert, J.

AU - Eckstein, J. N.

AU - Muller, D. A.

AU - Hellberg, C. Stephen

AU - Mannhart, J.

AU - Schlom, D. G.

PY - 2013/9/3

Y1 - 2013/9/3

N2 - 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 LaAlO3has been assumed perfect. Here we demonstrate, through experiments and first-principle calculations, that the cation stoichiometry of the nominal LaAlO3layer is key to 2-DEL formation: only Al-rich LaAlO3results in a 2-DEL. Although extrinsic defects, including oxygen deficiency, are known to render LaAlO3/SrTiO3samples 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.

AB - 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 LaAlO3has been assumed perfect. Here we demonstrate, through experiments and first-principle calculations, that the cation stoichiometry of the nominal LaAlO3layer is key to 2-DEL formation: only Al-rich LaAlO3results in a 2-DEL. Although extrinsic defects, including oxygen deficiency, are known to render LaAlO3/SrTiO3samples 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.

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U2 - 10.1038/ncomms3351

DO - 10.1038/ncomms3351

M3 - Journal article

SN - 2041-1723

VL - 4

JO - Nature Communications

JF - Nature Communications

M1 - 2351

ER -

LaAlO 3 stoichiometry is key to electron liquid formation at LaAlO 3/SrTiO 3 interfaces

Abstract

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