title: Parity-broken chiral spin dynamics in Ba₃NbFe₃Si₂O₁₄.
abstract: 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 the absence of macroscopic time-reversal symmetry breaking.
authors.affiliation: Institut Néel, CNRS and Université Joseph Fourier, BP166, 38042 Grenoble Cedex 9, France.
authors.forename: M
authors.initials: M
authors.lastname: Loire
authors.forename: V
authors.initials: V
authors.lastname: Simonet
authors.forename: S
authors.initials: S
authors.lastname: Petit
authors.forename: K
authors.initials: K
authors.lastname: Marty
authors.forename: P
authors.initials: P
authors.lastname: Bordet
authors.forename: P
authors.initials: P
authors.lastname: Lejay
authors.forename: J
authors.initials: J
authors.lastname: Ollivier
authors.forename: M
authors.initials: M
authors.lastname: Enderle
authors.forename: P
authors.initials: P
authors.lastname: Steffens
authors.forename: E
authors.initials: E
authors.lastname: Ressouche
authors.forename: A
authors.initials: A
authors.lastname: Zorko
authors.forename: R
authors.initials: R
authors.lastname: Ballou