Charge and spin order on the triangular lattice -- Na$_x$CoO$_2$ at $x=0.5$
| dc.creator | Zhou, Sen | |
| dc.creator | Wang, Ziqiang | |
| dc.date | 2006-08-02 | |
| dc.date | 2007-06-04 | |
| dc.date.accessioned | 2026-07-07T08:05:33Z | |
| dc.date.available | 2026-07-07T08:05:33Z | |
| dc.description | 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. | |
| dc.description | 4 pages, 4 figures, revtex4 file | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0608068 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0608068 | |
| dc.identifier | Phys. Rev. Lett. 98, 226402 (2007) | |
| dc.identifier | doi:10.1103/PhysRevLett.98.226402 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/130317 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.title | Charge and spin order on the triangular lattice -- Na$_x$CoO$_2$ at $x=0.5$ | |
| dc.type | text |