Impact of electric-field-dependent dielectric constants on two-dimensional electron gases in complex oxides

ORAL

Abstract

A high-density two-dimensional electron gas (2DEG) can be formed at interfaces of complex oxides. The electric field in the vicinity of the interface depends on the dielectric properties of the material as well as on the electron distribution. However, electric fields can strongly modify the dielectric constant of SrTiO$_3$ (STO) as well as other complex oxides. Solving the electrostatic problem thus requires a self-consistent approach in which the dielectric constant varies according to the local magnitude of the field. We have implemented the field dependence of the dielectric constant in a Schr\”odinger-Poisson solver and use the SrTiO$_3$/GdTiO$_3$ interface as an example to discuss the importance of taking this field dependence into account when modeling interfaces of complex oxides [1].\\ \newline [1] H. Peelaers, K. Krishnaswamy, L. Gordon, D. Steiauf, A. Sarwe, A. Janotti, and C. G. Van de Walle, Appl. Phys. Lett. {\bf 107}, 183505 (2015).

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Authors

  • Chris G. Van de Walle

    University of California, Santa Barbara, Univ of California - Santa Barbara, Materials Department, University of California, Santa Barbara, Materials Department, UC Santa Barbara, UCSB, University of California Santa Barbara

  • Hartwin Peelaers

    Univ of California - Santa Barbara, University of California, Santa Barbara

  • Karthik Krishnaswamy

    University of California, Santa Barbara, Univ of California - Santa Barbara

  • Luke Gordon

    Univ of California - Santa Barbara

  • Daniel Steiauf

    Univ of California - Santa Barbara

  • Anna Sarwe

    Univ of California - Santa Barbara

  • Anderson Janotti

    University of Delaware, Univ of Delaware, Univ of California - Santa Barbara, University of Delaware, Newark, Materials Science and Engineering, University of Delaware, Newark DE 19716, University of Delaware, Department of Materials Science and Engineering