Chiral fluctuations in triangular antiferromagnets (TAFs) at T≪TN are studied theoretically. The case of a ferromagnetic interaction along c axis (which is directed perpendicular to the plane of the lattice), Dzyaloshinskii-Moriya interaction D∥c and a weak magnetic field H∥c is considered in detail. Previously, this model has been proposed to describe quantum TAF CsCuCl3. Expressions for dynamical chirality (DC) are derived within the linear spin-wave approximation. In contrast to non-frustrated antiferromagnets, DC is found to be nonzero even at D,H=0 in a one-domain sample. We argue that this unusual behavior stems from the fact that a ground state of XY and Heisenberg TAFs is characterized by an axial vector along which DC is directed.
@article{arxiv.cond-mat/0507720,
title = {Chiral fluctuations in triangular antiferromagnets at $T \ll T_N$},
author = {A. V. Syromyatnikov},
journal= {arXiv preprint arXiv:cond-mat/0507720},
year = {2007}
}