116 research outputs found
Ab initio Evidence for Strong Correlation Associated with Mott Proximity in Iron-based Superconductors
We predict that iron-based superconductors discovered near d6 configuration
(5 Fe 3d orbitals filled by 6 electrons) is located on the foot of an
unexpectedly large dome of correlated electron matter centered at the Mott
insulator at d5 (namely, half filling). This is based on the many-variable
variational Monte-Carlo results for ab initio low-energy models derived by the
downfolding. The d5 Mott proximity extends to subsequent emergence of
incoherent metals, orbital differentiations due to the Mott physics and
Hund's-rule coupling, followed by antiferromagnetic quantum criticality, in
quantitative accordance with available experiments.Comment: 9 pages, 5 figure
Charge Order with a Noncoplanar Triple-Q Magnetic Order on a Cubic Lattice
Ground state of the periodic Anderson model on a cubic lattice is
investigated by mean-field calculations, with focusing on the possibility of
charge ordering. We show that three different charge-ordered phases appear at
3/2 filling, which are accompanied by ferromagnetic, noncoplanar triple-Q, and
ferrimagnetic order, respectively. The triple-Q magnetic order is likely
stabilized by emergent geometrical frustration in the charge-ordered phase with
the ordering wave vector (pi,pi,pi). We show that the nearest-neighbor hopping
between localized electrons stabilizes the triple-Q phase relative to the other
two phases. We also discuss the electronic structure in the triple-Q
charge-ordered phase.Comment: 6 pages, 3 figure
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