Electronic theory for itinerant in-plane magnetic fluctuations in Na$_x$CoO$_2$

Details Electronic theory for itinerant in-plane magnetic fluctuations in Na$_x$CoO$_2$ Electronic theory for itinerant in-plane magnetic fluctuations in Na$_x$CoO$_2$

2006-08-15

arxiv.org/abs/cond-mat/0608327v2

JETP Letters 84, 650 (2006) [Pis'ma v ZhETF 84, 769 (2006)]

Physics

Condensed Matter

Strongly Correlated Electrons

4 pages, 4 figures; LDA calculations were done with Na in the symmetric 2d position contrary to the 6h position in a previous

Scientific paper

10.1134/S0021364006240040

Starting from {\it ab-initio} band structure for Na$_x$CoO$_2$, we derive the single-electron energies and the effective tight-binding description for the $t_{2g}$ bands using a projection procedure. We find that due to the presence of the next-nearest-neighbor hoppings a local minimum in the electronic dispersion close to the $\Gamma$ point of the first Brillouin zone forms. Therefore, in addition to a large Fermi surface an electron pocket close to the $\Gamma$ point emerges at high doping concentrations. The latter yields the new scattering channel resulting in a peak structure of the itinerant magnetic susceptibility at small momenta. This indicates itinerant in-plane ferromagnetic state above certain critical concentration $x_m$, in agreement with neutron scattering data. Below $x_m$ the magnetic susceptibility shows a tendency towards the antiferromagnetic fluctuations. We estimate the value of $0.58 < x_m < 0.7$ within the rigid band model and within the Hubbard model with infinite on-site Coulomb repulsion consistent with the experimental phase diagram.

Affiliated with

Also associated with

No associations

Rating

Electronic theory for itinerant in-plane magnetic fluctuations in Na$_x$CoO$_2$ 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 Electronic theory for itinerant in-plane magnetic fluctuations in Na$_x$CoO$_2$, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronic theory for itinerant in-plane magnetic fluctuations in Na$_x$CoO$_2$ will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-99420