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Concomitant appearance of conductivity and superconductivity in (111) LaAlO<sub>3</sub>/SrTiO<sub>3</sub> interface with metal capping

ORAL

Abstract

In (111) SrTiO3/LaAlO3 interface, a critical thickness of nine monolayers (ML) of epitaxial LaAlO3 is required for conductivity to appear. We show that this critical thickness always decreases when depositing a metallic over-layer. The critical thickness is only 3ML for cobalt overlayer and 6ML for platinum. The latter result contrasts with the (100) interface where a platinum overlayer increases the critical thickness beyond that of the bare interface [1]. These results suggest that the work function of the metallic overlayer plays an important role in both interfaces. Interestingly, for (111) SrTiO3/LaAlO3/Metal interfaces conductivity appears concomitantly with superconductivity in contrast with the (100) SrTiO3/LaAlO3/Metal interface with LaAlO3 layer smaller than four unit-cells, which are conducting but not superconducting. We suggest that this difference is related to the different sub-bands involved in conductivity for the (111) interfaces comparing to the (100) interfaces [2]. Our findings can be useful for superconducting tunnelling devices.

References
1. D. C. Vaz et al., Adv. Mater., 29,1700486 (2017)
2. Udit Khanna et al., Phys. Rev. Lett., 123, 036805 (2019)

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Presenters

  • Ravindra Bisht

    Tel Aviv University

Authors

  • Ravindra Bisht

    Tel Aviv University

  • Michael Mograbi

    Tel Aviv University

  • Prasanna Rout

    Tel Aviv University, QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands

  • Gal Tuvia

    Tel Aviv University

  • Hyeok Yoon

    Department of Applied Physics, Stanford University, Standford University

  • Adrian G Swartz

    Standford University

  • Harold Hwang

    Department of Applied Physics, Stanford University, Stanford Institute for Materials and Energy Sciences, SLAC - Natl Accelerator Lab, Stanford Univ, Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Stanford University, Standford University, Stanford Institute for Materials and Energy Sciences, Stanford University and SLAC National Accelerator Laboratory, SIMES, SLAC, Applied Physics, Stanford University

  • Yoram Dagan

    Tel Aviv University, Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Department of Condensed Matter Physics, Tel Aviv University, Tel Aviv, 6997801, Israel