Tuning the Rashba Effect with Electrical Gating of Ultra-thin LaTiO3/SrTiO3 Heterostructures

ORAL

Abstract

Emergent metallic behavior at the interface of the Mott insulator LaTiO3 and the band insulator SrTiO3 has been explained in terms of charge redistribution at the interface combined with strain-induced electronic structure modification. We have studied ultra thin (3 unit cells) films of LaTiO3 and found evidence for a giant Rashba effect from quantum oscillations with an associated Berry phase, weak antilocalization in the magnetoresistance, and anisotropic in-plane magnetoresistance. In order to tune these properties, we have electrically back-gated these films. We have found a transition from a nonlinear to a linear Hall effect, a change in sign of the magnetoresistance, and, most interestingly, a peak in the zero field resistance. Based on density functional theory calculations, we attribute the nonlinear to linear Hall effect transition to an emptying of a dxz+yz band. The peak is attributed to tuning the Fermi energy across a Rashba effect induced Dirac point.

–

Presenters

  • Michael Veit

    Stanford Univ, Stanford University

Authors

  • Michael Veit

    Stanford Univ, Stanford University

  • Remi Arras

    University of Toulouse

  • Brad Ramshaw

    Cornell University, Los Alamos National Labs, National High Magnetic Field Laboratory, Department of Physics, Cornell University, Laboratory of Atomic and Solid State Physics, Cornell University, Los Alamos National Laboratory, Laboratory for Atomic and Solid state Physics, Cornell University

  • Mun Chan

    National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos National Laboratory, National High Magnetic Field Laboratory

  • Rossitza Pentcheva

    University of Duisburg-Essen, Department of Physics, Universität Duisburg-Essen, Department of Physics and CENIDE, University of Duisburg-Essen

  • Yuri Suzuki

    Applied Physics, Stanford University, Stanford Univ, Stanford University