Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface

A Corrigendum to this article was published on 04 May 2006


Polarity discontinuities at the interfaces between different crystalline materials (heterointerfaces) can lead to nontrivial local atomic and electronic structure, owing to the presence of dangling bonds and incomplete atomic coordinations1,2,3. These discontinuities often arise in naturally layered oxide structures, such as the superconducting copper oxides and ferroelectric titanates, as well as in artificial thin film oxide heterostructures such as manganite tunnel junctions4,5,6. If polarity discontinuities can be atomically controlled, unusual charge states that are inaccessible in bulk materials could be realized. Here we have examined a model interface between two insulating perovskite oxides—LaAlO3 and SrTiO3—in which we control the termination layer at the interface on an atomic scale. In the simple ionic limit, this interface presents an extra half electron or hole per two-dimensional unit cell, depending on the structure of the interface. The hole-doped interface is found to be insulating, whereas the electron-doped interface is conducting, with extremely high carrier mobility exceeding 10,000 cm2 V-1 s-1. At low temperature, dramatic magnetoresistance oscillations periodic with the inverse magnetic field are observed, indicating quantum transport. These results present a broad opportunity to tailor low-dimensional charge states by atomically engineered oxide heteroepitaxy.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Growth and schematic models of the two possible interfaces between LaAlO3 and SrTiO3 in the (001) orientation.
Figure 2: Transport properties of the (LaO)+/(TiO2)0 interface for different oxygen partial pressures p O 2 during growth at 10-4, 10-5, and 10-6 torr, as well as for 10-6 torr growth followed by annealing in 1 atm of O2 at 400 °C for 2 h.
Figure 3: Low-temperature magnetoresistance of the (LaO)+/(TiO2)0 interface between 60-Å-thick LaAlO3 and SrTiO3 grown at 10-6 torr p O 2 .
Figure 4: The dependence of -1/RHe at 2 K on the p O 2 during growth for the samples in this study.


  1. 1

    Baraff, G. A., Appelbaum, J. A. & Hamann, D. R. Self-consistent calculation of the electronic structure at an abrupt GaAs-Ge interface. Phys. Rev. Lett. 38, 237–240 (1977)

    ADS  CAS  Article  Google Scholar 

  2. 2

    Harrison, W. A., Kraut, E. A., Waldrop, J. R. & Grant, R. W. Polar heterojunction interfaces. Phys. Rev. B 18, 4402–4410 (1978)

    ADS  CAS  Article  Google Scholar 

  3. 3

    Kroemer, H. Polar-on-nonpolar epitaxy. J. Cryst. Growth 81, 193–204 (1987)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Bednorz, J. G. & Mueller, K. A. Possible high-Tc superconductivity in the Ba-La-Cu-O system. Z. Phys. B 64, 189–193 (1986)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Park, B. H. et al. Lanthanum-substituted bismuth titanate for use in non-volatile memories. Nature 401, 682–684 (1999)

    ADS  CAS  Article  Google Scholar 

  6. 6

    Tokura, Y. R. (ed.) Colossal Magnetoresistive Oxides Ch. 9, 10 (Gordon and Breach, New York, 2000)

  7. 7

    Wang, T., Moll, N., Cho, K. & Joannopoulos, J. D. Deliberately designed materials for optoelectronics applications. Phys. Rev. Lett. 82, 3304–3307 (1999)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Ruddlesden, S. N. & Popper, P. New compounds of the K2NiF4 type. Acta Crystallogr. 10, 538–540 (1957)

    CAS  Article  Google Scholar 

  9. 9

    Ruddlesden, S. N. & Popper, P. The compound Sr3Ti2O7 and its structure. Acta Crystallogr. 11, 54–55 (1958)

    CAS  Article  Google Scholar 

  10. 10

    Robinson, P., Harrison, R. J., McEnroe, S. A. & Hargraves, R. B. Lamellar magnetism in the haematite–ilmenite series as an explanation for strong remanent magnetization. Nature 418, 517–520 (2002)

    ADS  CAS  Article  Google Scholar 

  11. 11

    Kawasaki, M. et al. Atomic control of the SrTiO3 crystal-surface. Science 266, 1540–1542 (1994)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Kim, D. W. et al. Roles of the first atomic layers in growth of SrTiO3 films on LaAlO3 substrates. Appl. Phys. Lett. 74, 2176–2178 (1999)

    ADS  CAS  Article  Google Scholar 

  13. 13

    Tufte, O. N. & Chapman, P. W. Electron mobility in semiconducting strontium titanate. Phys. Rev. 155, 796–802 (1967)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Lide, D. R. (ed.) CRC Handbook of Chemistry and Physics, 77th edn (CRC Press, Boca Raton, 1996)

  15. 15

    Tokura, Y. et al. Filling dependence of electronic properties on the verge of metal-Mott-insulator transitions in Sr1-xLaxTiO3 . Phys. Rev. Lett. 70, 2126–2129 (1993)

    ADS  CAS  Article  Google Scholar 

  16. 16

    Francis, R. J., Moss, S. C. & Jacobson, A. J. X-ray truncation rod analysis of the reversible temperature-dependent [001] surface structure of LaAlO3 . Phys. Rev. B 64, 235425 (2001)

    ADS  Article  Google Scholar 

  17. 17

    Frederikse, H. P. R., Hosler, W. R. & Thurber, W. R. Shubnikov-de Haas effect in SrTiO3 . Phys. Rev. 158, 775–778 (1967)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Fano, U. Effects of configuration interaction on intensities and phase shifts. Phys. Rev. 124, 1866–1878 (1961)

    ADS  CAS  Article  Google Scholar 

  19. 19

    Pippard, A. B. Magnetoresistance in Metals Ch. 6 (Cambridge Univ. Press, Cambridge, 1989)

    Google Scholar 

  20. 20

    Sakudo, T. & Unoki, H. Dielectric properties of SrTiO3 at low temperatures. Phys. Rev. Lett. 26, 851–853 (1971)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Nishimura, T. et al. Structure change of TiO2-terminated SrTiO3(001) surfaces by annealing in O2 atmosphere and ultrahigh vacuum. Surf. Sci. 421, 273–278 (1999)

    ADS  CAS  Article  Google Scholar 

  22. 22

    Herring, C. Effect of random inhomogeneities on electrical and galvanomagnetic measurements. J. Appl. Phys. 31, 1939–1953 (1960)

    ADS  Article  Google Scholar 

Download references


We thank D. Schlom, D. R. Hamann and T. Ohnishi for discussions. We acknowledge partial support from NEDO's International Joint Research Program. A.O. acknowledges partial support from the Asahi Glass Foundation and the Inamori Foundation.

Author information



Corresponding author

Correspondence to H. Y. Hwang.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ohtomo, A., Hwang, H. A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface. Nature 427, 423–426 (2004).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing