[en] The physical mechanisms responsible for the formation of a two-dimensional electron gas at the interface between insulating SrTiO3 and LaAlO3 have remained a contentious subject since its discovery in 2004. Opinion is divided between an intrinsic mechanism involving the build-up of an internal electric potential due to the polar discontinuity at the interface between SrTiO3 and LaAlO3, and extrinsic mechanisms attributed to structural imperfections. Here we show that interface conductivity is also exhibited when the LaAlO3 layer is diluted with SrTiO3, and that the threshold thickness required to show conductivity scales inversely with the fraction of LaAlO3 in this solid solution, and thereby also with the layer’s formal polarization. These results can be best described in terms of the intrinsic polar-catastrophe model, hence providing the most compelling evidence, to date, in favour of this mechanism.
Disciplines :
Physics
Author, co-author :
Reinle-Schmitt, M.L.
Cancellieri, C.
Li, D.
Fontaine, Denis ; Université de Liège - ULiège > Département de physique > Physique théorique des matériaux
Medarde, M.
Pomjakushina, E.
Schneider, C.W.
Gariglio, S.
Ghosez, Philippe ; Université de Liège - ULiège > Département de physique > Physique théorique des matériaux
Triscone, J.-M.
Willmott, P.R.
Language :
English
Title :
Tunable conductivity threshold at polar oxide interfaces
Publication date :
03 July 2012
Journal title :
Nature Communications
eISSN :
2041-1723
Publisher :
Nature Publishing Group, London, United Kingdom
Volume :
3
Pages :
932
Peer reviewed :
Peer Reviewed verified by ORBi
Tags :
Tier-1 supercomputer CÉCI : Consortium des Équipements de Calcul Intensif
scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.
Bibliography
Okamoto, S. & Millis, A. J. Electronic reconstruction at an interface between a Mott insulator and a band insulator. Nature 428, 630-633 (2004). (Pubitemid 38524800)
Ohtomo, A. & Hwang, H. Y. A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface. Nature 427, 423-426 (2004). (Pubitemid 38168490)
Gozar, A. et al. High-Temperature interface superconductivity between metallic and insulating copper oxides. Nature 455, 782-785 (2008).
Zubko, P., Gariglio, S., Gabay, M., Ghosez, P. & Triscone, J.-M. Interface physics in complex oxide heterostructures. Annu. Rev. Condens. Matter Phys. 2, 141-165 (2011).
Hwang, H. Y. et al. Emergent phenomena at oxide interfaces. Nat. Mater. 11, 103-113 (2012).
Nakagawa, N., Hwang, H. Y. & Muller, D. A. Why some interfaces cannot be sharp. Nat. Mater. 5, 204-209 (2006). (Pubitemid 43320635)
Thiel, S., Hammerl, G., Schmehl, A., Schneider, C. W. & Mannhart, J. Tunable quasi-Two-dimensional electron gases in oxide heterostructures. Science 313, 1942-1945 (2006). (Pubitemid 44497997)
Schlom, D. G. & Mannhart, J. Oxide electronics: interface takes charge over Si. Nat. Mater. 10, 168-169 (2011).
Huijben, M. et al. Electronically coupled complementary interfaces between perovskite band insulators. Nat. Mater. 5, 556-560 (2006). (Pubitemid 43993078)
Cancellieri, C. et al. Influence of the growth conditions on the LaAlO3/SrTiO3 interface electronic properties. Europhys. Lett. 91, 17004 (2010).
Popovic, Z. S., Satpathy, S. & Martin, R. M. Origin of the two-dimensional electron gas carrier density at the LaAlO3 on SrTiO3 interface. Phys. Rev. Lett. 101, 256801 (2008).
Lee, J. & Demkov, A. A. Charge origin and localization at the n-Type SrTiO3/LaAlO3 interface. Phys. Rev. B 78, 193104 (2008).
Siemons, W. et al. Origin of charge density at LaAlO3 on SrTiO 3 heterointerfaces: Possibility of intrinsic doping. Phys. Rev. Lett. 98, 196802 (2007).
Herranz, G. et al. High mobility in LaAlO3/SrTiO3 heterostructures: Origin, dimensionality and perspectives. Phys. Rev. Lett. 98, 216803 (2007).
Kalabukhov, A. et al. Effect of oxygen vacancies in the SrTiO3 substrate on the electrical properties of the LaAlO3/SrTiO3 interface. Phys. Rev. B 75, 121404(R) (2007).
Bristowe, N. C., Littlewood, P. B. & Artacho, E. Surface defects and conduction in polar oxide heterostructures. Phys. Rev. B 83, 205405 (2011).
Xie, Y., Hikita, Y., Bell, C. & Hwang, H. Y. Control of electronic conduction at an oxide heterointerface using surface polar adsorbates. Nat. Commun. 2, 494 (2011).
Willmott, P. R. et al. Structural basis for the conducting interface between LaAlO3 and SrTiO3. Phys. Rev. Lett. 99, 155502 (2007).
Qiao, L. et al. Thermodynamic instability at the stoichiometric LaAlO3/SrTiO3 (001) interface. J. Phys. Condens. Matter 22, 312201 (2010).
Qiao, L. et al. Epitaxial growth, structure, and intermixing at the LaAlO3/SrTiO3 interface as the film stoichiometry is varied. Phys. Rev. B 83, 085408 (2011).
Segal, Y., Ngai, J. H., Reiner, J. W., Walker, F. J. & Ahn, C. H. X-ray photoemission studies of the metal-insulator transition in LaAlO3/SrTiO3 structures grown by molecular beam epitaxy. Phys. Rev. B 80, 241107 (2009).
Pauli, S. A. et al. Evolution of the interfacial structure of LaAlO3 on SrTiO3. Phys. Rev. Lett. 106, 036101 (2011).
Cancellieri, C. et al. Electrostriction at the LaAlO3/SrTiO3 interface. Phys. Rev. Lett. 107, 056102 (2011).
Stengel, M. & Vanderbilt, D. Berry-phase theory of polar discontinuities at oxide-oxide interfaces. Phys. Rev. B 80, 241103 (2009).
Konaka, T., Sato, M., Asano, H. & Kubo, S. Relative permittivity and dielectric loss tangent of substrate materials for high-Tc superconducting film. J. Superconduct. 4, 283-288 (1991). (Pubitemid 21707580)
Bert, J. A. et al. Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface. Nat. Phys. 7, 767-771 (2011).
Gariglio, S., Reyren, N., Caviglia, A. D. & Triscone, J.-M. Superconductivity at the LaAlO3/SrTiO3 interface. J. Phys. Condens. Matter 21, 164213 (2009).
Stengel, M. & Spaldin, N. A. Origin of the dielectric dead layer in nanoscale capacitors. Nature 443, 679-682 (2006). (Pubitemid 44564708)
Sun, P. H. et al. Dielectric behavior of (1-x)LaAlO3 xSrTiO3 solid solution system at microwave frequencies. Jap. J. Appl. Phys. 37, 5625-5629 (1998).
Chen, Y. et al. Metallic and insulating interfaces of amorphous SrTiO3-based oxide heterostructures. Nano Lett. 11, 3774-3778 (2011).
Bilc, D. I. et al. Hybrid exchange-correlation functional for accurate prediction of the electronic and structural properties of ferroelectric oxides. Phys. Rev. B 77, 165107 (2008).
Wu, Z. & Cohen, R. E. More accurate generalized gradient approximation for solids. Phys. Rev. B 73, 235116 (2006).
Becke, A. D. Density-functional thermochemistry. IV. A new dynamical correlation functional and implications for exact-exchange mixing. J. Chem. Phys. 104, 1040-1046 (1996). (Pubitemid 126747264)
Delugas, P. et al. Spontaneous 2-dimensional carrier confinement at the n-Type SrTiO3/LaAlO3 interface. Phys. Rev. Lett. 106, 166807 (2011).
Dovesi, R. et al. CRYSTAL: a computational tool for the ab initio study of the electronic properties of crystals. Z. Kristallogr. 220, 571-573 (2005). (Pubitemid 40778243)
Bredow, T., Heitjans, P. & Wilkening, M. Electric field gradient calculations for LixTiS2 and comparison with 7Li NMR results. Phys. Rev. B 70, 115111 (2004).
Piskunov, S., Heifets, E., Eglitis, R. I. & Borstel, G. Bulk properties and electronic structure of SrTiO3, BaTiO3, PbTiO3 perovskites: an ab initio HF/DFT study. Comp. Mat. Sci. 29, 165-178 (2004).
Towler, M. CRYSTAL resource page, 2011, see www.tcm.phy.cam.ac.uk/mdt26/ crystal.html.
Cao, X. Y. & Dolg, M. Segmented contraction scheme for small-core lanthanide pseudopotential basis sets. J. Mol. Struct. Theochem. 581, 139-147 (2002).
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.