Abstract

Electrostatic fields tune the ground state of interfaces between complex oxide materials. Electronic properties, such as conductivity and superconductivity, can be tuned and then used to create and control circuit elements and gate-defined devices. Here we show that naturally occurring twin boundaries, with properties that are different from their surrounding bulk, can tune the LaAlO3/SrTiO3 interface 2DEG at the nanoscale. In particular, SrTiO3 domain boundaries have the unusual distinction of remaining highly mobile down to low temperatures, and were recently suggested to be polar. Here we apply localized pressure to an individual SrTiO3 twin boundary and detect a change in LaAlO3/SrTiO3 interface current distribution. Our data directly confirm the existence of polarity at the twin boundaries, and demonstrate that they can serve as effective tunable gates. As the location of SrTiO3 domain walls can be controlled using external field stimuli, our findings suggest a novel approach to manipulate SrTiO3-based devices on the nanoscale.

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Acknowledgements

Y.F., N.H., Y.S. and B.K. were supported by the European Research Council grant ERC-2014-STG-639792 and Israel Science Foundation grant ISF-1102/13 and ISF-1281/17. Z.C., Y.H. and H.Y.H. acknowledge support by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under contract DE-AC02–76SF00515 (Y.H.), and the Gordon and Betty Moore Foundation’s EPiQS Initiative through grant GBMF4415 (Z.C.). E.K.H.S. was supported by EPSRC grant EP/P024904/1.

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Affiliations

  1. Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel

    • Yiftach Frenkel
    • , Noam Haham
    • , Yishai Shperber
    •  & Beena Kalisky
  2. H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK

    • Christopher Bell
  3. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA

    • Yanwu Xie
    • , Yasuyuki Hikita
    •  & Harold Y. Hwang
  4. Department of Physics, Zhejiang University, Hangzhou 310027, China

    • Yanwu Xie
  5. Department of Applied Physics, Geballe Laboratory for Advanced Materials, Stanford University, 476 Lomita Mall, Stanford University, Stanford, California 94305, USA

    • Yanwu Xie
    • , Zhuoyu Chen
    •  & Harold Y. Hwang
  6. Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK

    • Ekhard K. H. Salje
  7. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China

    • Ekhard K. H. Salje

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Contributions

Y.F., Y.S. and B.K. designed the experiment and performed the measurements. C.B., Y.X., Z.C., Y.H. and H.Y.H. provided the samples, N.H. contributed to the simulations and E.K.H.S. contributed to the interpretation of the data. Y.F. and B.K. prepared the manuscript with input from all co-authors.

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The authors declare no competing financial interests.

Corresponding author

Correspondence to Beena Kalisky.

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https://doi.org/10.1038/nmat4966

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