J_1-J_2 frustrated two-dimensional Heisenberg model: Random phase approximation and functional renormalization group

Details J_1-J_2 frustrated two-dimensional Heisenberg model: Random phase approximation and functional renormalization group J_1-J_2 frustrated two-dimensional Heisenberg model: Random phase approximation and functional renormalization group

2009-12-04

arxiv.org/abs/0912.0860v2

Phys. Rev. B 81, 144410 (2010)

Physics

Condensed Matter

Strongly Correlated Electrons

18 pages, 17 figures

Scientific paper

10.1103/PhysRevB.81.144410

We study the ground state properties of the two-dimensional spin-1/2 J_1-J_2-Heisenberg model on a square lattice, within diagrammatic approximations using an auxiliary fermion formulation with exact projection. In a first approximation we assume a phenomenological width of the pseudofermion spectral function to calculate the magnetization, susceptibilities and the spin correlation length within RPA, demonstrating the appearance of a paramagnetic phase between the Neel ordered and Collinear ordered phases, at sufficiently large pseudo fermion damping. Secondly we use a Functional Renormalization Group formulation. We find that the conventional truncation scheme omitting three-particle and higher order vertices is not sufficient. We therefore include self-energy renormalizations in the single-scale propagator as recently proposed by Katanin, to preserve Ward identities in a better way. We find Neel order at g = J_2/J_1 < 0.4 ... 0.45 and Collinear order at g > 0.66 ... 0.68, which is in good agreement with results obtained by numerical studies. In the intervening quantum paramagnetic phase we find enhanced columnar dimer and plaquette fluctuations of equal strength.

Affiliated with

Also associated with

No associations

Rating

J_1-J_2 frustrated two-dimensional Heisenberg model: Random phase approximation and functional renormalization group 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 J_1-J_2 frustrated two-dimensional Heisenberg model: Random phase approximation and functional renormalization group, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and J_1-J_2 frustrated two-dimensional Heisenberg model: Random phase approximation and functional renormalization group will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-420817