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Electric-field-induced superconductivity in an insulator

Nature Materials volume 7, pages 855858 (2008) | Download Citation

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Abstract

Electric field control of charge carrier density has long been a key technology to tune the physical properties of condensed matter, exploring the modern semiconductor industry. One of the big challenges is to increase the maximum attainable carrier density so that we can induce superconductivity in field-effect-transistor geometry. However, such experiments have so far been limited to modulation of the critical temperature in originally conducting samples because of dielectric breakdown1,2,3,4. Here we report electric-field-induced superconductivity in an insulator by using an electric-double-layer gating in an organic electrolyte5. Sheet carrier density was enhanced from zero to 1014 cm−2 by applying a gate voltage of up to 3.5 V to a pristine SrTiO3 single-crystal channel. A two-dimensional superconducting state emerged below a critical temperature of 0.4 K, comparable to the maximum value for chemically doped bulk crystals6, indicating this method as promising for searching for unprecedented superconducting states.

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Acknowledgements

We thank S. Maekawa, M. Mori, N. Reyren, J.-M. Triscone and A. Tsukazaki for fruitful discussions.

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Affiliations

  1. WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan

    • K. Ueno
    •  & M. Kawasaki
  2. Center for Low Temperature Science, Tohoku University, Sendai 980-8577, Japan

    • S. Nakamura
    • , N. Kimura
    • , T. Nojima
    •  & H. Aoki
  3. Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan

    • H. Shimotani
    • , A. Ohtomo
    • , Y. Iwasa
    •  & M. Kawasaki
  4. CREST, Japan Science and Technology Agency, Tokyo 102-0075, Japan

    • Y. Iwasa
    •  & M. Kawasaki

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Correspondence to K. Ueno or M. Kawasaki.

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https://doi.org/10.1038/nmat2298

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