paper

Phase diagram of the spin-1/2 -- Heisenberg model on the square lattice

arXiv:0907.4163 · doi:10.1088/1742-6596/200/2/022058

Abstract

We presents the results of an extensive numerical study of the phase diagram of the spin-1/2, \protect{--} Heisenberg model on a square lattice, for both ferromagnetic and antiferromagnetic nearest-neighbor interactions , using exact diagonalization with periodic and twisted boundary conditions. Comparison is made with published spin wave calculations. We show that quantum fluctuations play a very important role, changing both the extent and the wave vector of classical spiral phases, and leading to new quantum phases where the classical spiral states have a high degeneracy. These include a new phase with small or vanishing spin-stiffness, in addition to known valence-bond-solid and bond-nematic phases.

submitted for the International Conference on Magnetism to be held 26-31 July 2009 in Karlsruhe

References in corpus (3)

Cited by in corpus (35)