Strong influence of the complex bandstructure on the tunneling electroresistance: A combined model and ab-initio study

Abstract

The tunneling electroresistance (TER) for ferroelectric tunnel junctions (FTJs) with BaTiO_{3} (BTO) and PbTiO}_{3} (PTO) barriers is calculated by combining the microscopic electronic structure of the barrier material with a macroscopic model for the electrostatic potential which is caused by the ferroelectric polarization. The TER ratio is investigated in dependence on the intrinsic polarization, the chemical potential, and the screening properties of the electrodes. A change of sign in the TER ratio is obtained for both barrier materials in dependence on the chemical potential. The inverse imaginary Fermi velocity describes the microscopic origin of this effect; it qualitatively reflects the variation and the sign reversal of the TER. The quantity of the imaginary Fermi velocity allows to obtain detailed information on the transport properties of FTJs by analyzing the complex bandstructure of the barrier material.

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References in corpus (10)

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• Giant Tunneling Electroresistance Effect Driven by an Electrically Controlled Spin Valve at a Complex Oxide Interface
• Tunneling Electroresistance Induced by Interfacial Phase Transitions in Ultrathin Oxide Heterostructures
• First-principles studies of multiferroic and magnetoelectric materials
• Computational design of NDR tunnel diodes with high peak-to-valley current ratio based on two-dimensional cold metals: The case of NbSi${}_2$N${}_4$/HfSi${}_2$N${}_4$/NbSi${}_2$N${}_4$ lateral heterojunction diode
• First-principles study of metal-induced gap states in metal/oxide interfaces and their relation with the complex band structure
• Non-equilibrium Green's Function and First Principle Approach to Modeling of Multiferroic Tunnel Junctions