Fingerprints of interface superconductivity in ferroelectric tunnel junctions

ORAL

Abstract

Ferroelectric tunnel junctions open the possibility of controlling the tunneling current with the ferroelectric state of the barrier. We have studied ferroelectric tunnel junctions with La0.7Sr0.3MnO3 (LSMO) bottom electrode, a ferroelectric (FE) BaTiO3 barrier and La0.84Sr0.16CuO3-δ (LSCO) top electrode. LSCO is a cuprate capable of hosting large densities of oxygen vacancies (OV), yet superconductivity has never been observed. Coupled switching of oxygen vacancies and the ferroelectric polarization may produce drastic changes of the doping of the interface yielding unexpected electronic phases. We have found that the removal of OV from the cuprate interface has a strong hole doping effect of the material. We have observed the emergence of a new gap in the tunneling differential conductance curves which scales with temperature as a superconducting gap, strongly suggesting the nucleation of a superconducting phase at the interface. Switching the ferroelectric polarization of the barrier with an external electric field enables turning the superconducting gap on and off suggesting the possibility of the field effect control of the interface superconductivity.

*National project: Interface devices with tunable electronic structure and spin Memristors MAT2014-52405-C2-2-R

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Presenters

  • Fernando Gallego

    • 2D Foundry, Instituto de Ciencia de Materiales de Madrid
    • Universidad Complutense de Madrid

Authors

  • Fernando Gallego

    • 2D Foundry, Instituto de Ciencia de Materiales de Madrid
    • Universidad Complutense de Madrid

  • Victor Rouco

    • Física de Materiales, Universidad Complutense de Madrid

  • Mariona Cabero

    • Centro Nacional de Microscopia electronica, Universidad Complutense de Madrid

  • David Sanchez Manzano

    • Física de Materiales, Universidad Complutense de Madrid

  • Javier Tornos

    • Física de Materiales, Universidad Complutense de Madrid
    • Universidad Complutense de Madrid

  • Ralph El Hage

    • Unité Mixté de physique, CNRS

  • Kevin Seurre

    • Unité mixte de physique CNRS-Thales, Palaiseau, France
    • Unité Mixté de physique, CNRS

  • Fabian Andres Cuellar

    • Física de Materiales, Universidad Complutense de Madrid

  • Alberto Rivera-Calzada

    • Física de Materiales, Universidad Complutense de Madrid

  • Zouhair Sefrioui

    • Física de Materiales, Universidad Complutense de Madrid

  • Federico Mompean

    • 2D Foundry, Instituto de Ciencia de Materiales de Madrid

  • Mar Garcia-Hernandez

    • 2D Foundry, Instituto de Ciencia de Materiales de Madrid
    • Instituto de Ciencia de Materiales de Madrid - CSIC

  • Jose Maria Gonzalez-Calbet

    • Centro Nacional de Microscopia electronica, Universidad Complutense de Madrid

  • Javier Villegas

    • Unité mixte de physique CNRS-Thales, Palaiseau, France
    • Unité Mixte de Physique CNRS/Thales, Palaiseau, France
    • Unité Mixté de physique, CNRS

  • Carlos Leon

    • Física de Materiales, Universidad Complutense de Madrid

  • Jacobo Santamaria

    • GFMC, Universidad Complutense de Madrid, Spain
    • Física de Materiales, Universidad Complutense de Madrid
    • Universidad Complutense de Madrid