A diagrammatic theory of the antiferromagnetic frustrated 2d Heisenberg model

J. Reuther and P. Wölfle

We consider the ground state properties of the two-dimensional spin-1/2 J1-J2-Heisenberg model on a square lattice. Within a diagrammatic formulation in terms of auxiliary fermions we consider two different approximation schemes. First we use a phenomenological assumption on the width of the pseudofermion spectral function to calculate the magnetization and the correlation length within RPA with qualitatively correct results. Secondly we employ a Functional Renormalization Group formulation to obtain quantitative results on the ground state correlations. We discuss two different projection schemes to account for the auxiliary particle constraint.

Title
A diagrammatic theory of the antiferromagnetic frustrated 2d Heisenberg model
Author
J. Reuther and P. Wölfle
Publisher
Journal of Physics
Keywords
Condensed Matter
Type
Text