The spin wave excitations emerging from the chiral helically modulated 120∘ magnetic order in a langasite Ba3NbFe3Si2O14 enantiopure crystal were investigated by unpolarized and polarized inelastic neutron scattering. A dynamical fingerprint of the chiral ground state is obtained, singularized by (i) spectral weight asymmetries answerable to the structural chirality and (ii) a full chirality of the spin correlations observed over the whole energy spectrum. The intrinsic chiral nature of the spin waves elementary excitations is shown in absence of macroscopic time reversal symmetry breaking.
@article{arxiv.1010.2008,
title = {Parity Broken Chiral Spin Dynamics in Ba$_3$NbFe$_3$Si$_2$O$_{14}$},
author = {Mickael Loire and Virginie Simonet and Sylvain Petit and Karol Marty and Pierre Bordet and Pascal Lejay and Jacques Ollivier and Mechthild Enderle and Paul Steffens and Eric Ressouche and Andrej Zorko and Rafik Ballou},
journal= {arXiv preprint arXiv:1010.2008},
year = {2011}
}