Title: Degenerate and chiral states in the extended Heisenberg model in the kagome lattice,
Abstract: We present a study of the low temperature phases of the antiferromagnetic
extended classical Heisenberg model in the kagome lattice, up to third nearest
neighbors. First, we focus on the degenerate lines in the boundaries of the
well-known staggered chiral phases. These boundaries have either semi-extensive
or extensive degeneracy, and we discuss the partial selection of states by
thermal fluctuations. Then, we study the model under an external magnetic field
on these lines and in the staggered chiral phases. We pay particular attention
to the highly frustrated point, where the three exchange couplings are equal.
We show that this point can me mapped to a model with spin liquid behavior and
non-zero chirality. Finally, we explore the effect of Dzyaloshinskii-Moriya
(DM) interactions in two ways: an homogeneous and a staggered DM interaction.
In both cases, there is a rich low temperature phase diagram, with different
spontaneously broken symmetries and non trivial chiral phases.