Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2006-08-02
Phys. Rev. Lett. 98, 226402 (2007)
Physics
Condensed Matter
Strongly Correlated Electrons
4 pages, 4 figures, revtex4 file
Scientific paper
10.1103/PhysRevLett.98.226402
The nature of electronic states due to strong correlation and geometric frustration on the triangular lattice is investigated in connection to the unconventional insulating state of Na$_x$CoO$_2$ at $x=0.5$. We study an extended Hubbard model using a spatially unrestricted Gutzwiller approximation. We find a new class of charge and spin ordered states at $x=1/3$ and $x=0.5$ where antiferromagnetic (AF) frustration is alleviated via weak charge inhomogeneity. At $x=0.5$, we show that the $\sqrt{3}a\times2a$ off-plane Na dopant order induces weak $\sqrt{3}a\times1a$ charge order in the Co layer. The symmetry breaking enables successive $\sqrt{3}a\times1a$ AF and $2a\times2a$ charge/spin ordering transitions at low temperatures. The Fermi surface is truncated by the $2a\times2a$ hexagonal zone boundary into small electron and hole pockets. We study the phase structure and compare to recent experiments.
Wang Ziqiang
Zhou Sen
No associations
LandOfFree
Charge and spin order on the triangular lattice -- Na$_x$CoO$_2$ at $x=0.5$ does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Charge and spin order on the triangular lattice -- Na$_x$CoO$_2$ at $x=0.5$, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Charge and spin order on the triangular lattice -- Na$_x$CoO$_2$ at $x=0.5$ will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-50102