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Probing the superconductivity of ferroelectric SrTiO<sub>3 </sub>films

ORAL

Abstract

We report on the superconducting characteristics of doped 180-nm-thick SrTiO3 films, grown by molecular beam epitaxy on (001) LSAT substrates. The epitaxial compressive strain induced by the substrate stabilizes a ferroelectric phase in the SrTiO3 for carrier concentrations ranging from 5×1019 – 1.5×1020 cm-3 [1,2]. A systematic study of the critical temperature and critical field as a function of the carrier density and type of doping atom reveal deviations from those expected for a single-band BCS superconductor. In particular, the critical temperature and critical field show qualitative different evolutions, with the latter exceeding the Pauli limit for certain values. We discuss the role of the band structure and inversion symmetry breaking.

[1] K. Ahadi, et al., Sci. Adv. 5, eaaw0120 (2019).
[2] R. Russell, et al., Phys. Rev. Mater. 3, 091401(R) (2019).

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Presenters

  • Timo Schumann

    Materials, UC Santa Barbara, University of California, Santa Barbara

Authors

  • Timo Schumann

    Materials, UC Santa Barbara, University of California, Santa Barbara

  • Luca Galletti

    Materials, UC Santa Barbara, Materials, University of California, Santa Barbara, University of California, Santa Barbara

  • Kaveh Ahadi

    NC State University, University of California, Santa Barbara

  • Hanbyeol Jeong

    University of California, Santa Barbara

  • Susanne Stemmer

    Materials, UC Santa Barbara, University of California, Santa Barbara, Materials, University of California, Santa Barbara