TY - JOUR
T1 - Tunable metal-insulator transition, Rashba effect and Weyl Fermions in a relativistic charge-ordered ferroelectric oxide
AU - He, Jiangang
AU - Di Sante, Domenico
AU - Li, Ronghan
AU - Chen, Xing Qiu
AU - Rondinelli, James M.
AU - Franchini, Cesare
N1 - Funding Information:
Work at the University of Vienna was sponsored by the FWF project INDOX (Grant No. I1490-N19). Work at the Shenyang National Laboratory for Materials Science was supported by the National Science Fund for Distinguished Young Scholars (No. 51725103), by the National Natural Science Foundation of China (Grant Nos. 51671193 and 51474202), and by the Science Challenging Project No. TZ2016004. D.D.S. was supported by the German Research Foundation (DFG-SFB 1170) and acknowledges the ERC-StG-336012-Thomale-TOPOLECTRICS. J.M.R. was supported by the Army Research Office (W911NF-15-1-0017). All calculations were performed on the Vienna Scientific Cluster (VSC) and partially at the high-performance computational cluster in the Shenyang National University Science and Technology Park, as well as the National Supercomputing Center in Guangzhou (TH-2 system).
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - 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.
AB - 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.
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U2 - 10.1038/s41467-017-02814-4
DO - 10.1038/s41467-017-02814-4
M3 - Article
C2 - 29402881
AN - SCOPUS:85041694671
SN - 2041-1723
VL - 9
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 492
ER -