Emergence of superconductivity on a SrTiO3 surface by electric-field charge accumulation

K. Ueno, S. Nakamura, H. Shimotani, T. Nojima, Y. Iwasa, M. Kawasaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We briefly review principles and main features of an electric double layer transistor (EDLT) as well as electric field induced superconductivity in SrTiO3. EDLT is a field-effect transistor that employs an electrolyte as a gate dielectric. An electric double layer between a semiconductor and the electrolyte attains much higher breakdown field than the maximum of a solid gate dielectric, resulting in high density charge accumulation up to 10 14cm-2. That density is sufficient for inducing new physical phases, such as superconductivity and ferromagnetism, on various oxide systems. We employed a surface of a SrTiO3 single crystal as a semiconductor channel. We have demonstrated insulator-tosuperconductor transition by electric field-effect without chemical doping. Charge carrier density was linearly increased from zero to 1014 cm-2 with increasing gate bias to 3.5 V. Superconducting critical parameters, such as critical temperature Tc, critical magnetic field Hc, and critical current density Jc were examined as a function of carrier density by varying gate bias. Tc was almost constant as a function of the carrier density, contrasting to bell-shaped dependence of Hc and Jc. Temperature dependence of I-V curve shows the BKT-type transition, which indicates two-dimensional superconductivity in the electric field induced superconductivity.

Original languageEnglish
Title of host publicationOxide-Based Materials and Devices II
Publication statusPublished - 2011
EventOxide-Based Materials and Devices II - San Francisco, CA, United States
Duration: 2011 Jan 232011 Jan 26

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherOxide-Based Materials and Devices II
Country/TerritoryUnited States
CitySan Francisco, CA


  • carrier doping
  • electric double layer transistor
  • electrochemical transistor
  • electrolyte
  • field effect transistor
  • oxide semiconductor
  • superconductivity
  • two dimensional electron gas

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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