Title
Tunable metal-insulator transition, Rashba effect and Weyl Fermions in a relativistic charge-ordered ferroelectric oxide
Author
Domenico Di Sante
Institut für Theoretische Physik und Astrophysik, Universität Würzburg
Author
Ronghan Li
Shenyang National Laboratory for Materials Science
... show all
Abstract
Controllable metal–insulator transitions (MIT), Rashba–Dresselhaus (RD) spin splitting, and Weyl semimetals are promising schemes for realizing processing devices. Complex oxides are a desirable materials platform for such devices, as they host delicate and tunable charge, spin, orbital, and lattice degrees of freedoms. Here, using first-principles calculations and symmetry analysis, we identify an electric-field tunable MIT, RD effect, and Weyl semimetal in a known, charge-ordered, and polar relativistic oxide Ag2BiO3 at room temperature. Remarkably, a centrosymmetric BiO6 octahedral-breathing distortion induces a sizable spontaneous ferroelectric polarization through Bi3+/Bi5+ charge disproportionation, which stabilizes simultaneously the insulating phase. The continuous attenuation of the Bi3+/Bi5+ disproportionation obtained by applying an external electric field reduces the band gap and RD spin splitting and drives the phase transition from a ferroelectric RD insulator to a paraelectric Dirac semimetal, through a topological Weyl semimetal intermediate state. These findings suggest that Ag2BiO3 is a promising material for spin-orbitonic applications.
Keywords
Electronic properties and materialsFerroelectrics and multiferroicsTopological matter
Object type
Language
English [eng]
Persistent identifier
https://phaidra.univie.ac.at/o:1067262
Appeared in
Title
Nature Communications
Volume
9
Publisher
Springer Science and Business Media LLC
Date issued
2018
Access rights
Rights statement
© The Author(s) 2018
University of Vienna | Universitätsring 1 | 1010 Vienna | T +43-1-4277-0