XXXVI Reunión Bienal de la Real Sociedad Española de Física

Realization of a Ferroelectric-Domain-Wall Tunnel Junction

18 Jul 2017, 17:50

20m

Aula Química Inorgánica (Facultad Química (USC))

Quantum Materials and Technologies (GEFES) Quantum Materials and Technologies (GEFES) I

Description

Harnessing the electronic response of ferroelectric thin films may be key in the realization of the visionary concept “The Wall is the Device” [1] towards future non-volatile memories, logic elements or energy-harvesting devices. While extensive work has been devoted to exploit the technological opportunities of the ferroelectric ground state in ultrathin films, and to understand the nature and properties of its domain walls, they have yet to be incorporated into an active device element [2,3]. Here we show results of a magnetic tunnel junction device consisting of a ferroelectric BaTiO3 tunnel barrier just 4.4-nanometer thick, with ferromagnetic La0.7Sr0.3MnO3 electrodes, containing a head-to-head domain wall within its thickness. A confined electron gas is formed at the ferroelectric domain wall, stabilized by oxygen vacancies, which controls the tunneling transport of the magnetic tunnel junction. Resonant tunneling assisted by the discrete levels of the ferroelectric quantum well gives rise to strong quantum oscillations of the tunneling conductance. Our engineered, highly constrained, domain wall provides a major step forward towards exploiting the electronic properties of domain walls for ferroelectric tunnel barriers with new functionalities [4].