paper

Spiral antiferromagnets beyond the spin-wave approximation: frustrated and Heisenberg models in the honeycomb lattice

arXiv:1312.4558 · doi:10.1103/PhysRevB.89.094413

Abstract

We examine the stability of classical states with a generic incommensurate spiral order against quantum fluctuations. Specifically, we focus on the frustrated spin-1/2 and Heisenberg models on the honeycomb lattice with nearest-neighbor and next-nearest-neighbor antiferromagnetic couplings. Our variational approach is based on the Jastrow wave functions, which include quantum correlations on top of classical spin waves. We perform a systematic optimization of wave vectors and Jastrow pseudo-potentials within this class of variational states and find that quantum fluctuations favor collinear states over generic coplanar spirals. The Néel state with extends its stability well beyond the classical value . Most importantly, the collinear states with (and the two symmetry-related states) are found to be stable in a large regime with intermediate frustration, while at the classical level they are limited to the point . For large frustration, the state is stabilized for finite values of in both models.

10 pages, 10 figures, 4 tables

References in corpus (4)

Cited by in corpus (22)