Role of Antisymmetric Exchange in Selecting Magnetic Chirality in   Ba$_3$NbFe$_3$Si$_2$O$_{14}$
  We present electron spin resonance (ESR) investigation of the acentric \FeLang, featuring a unique single-domain double-chiral magnetic ground state. Combining simulations of the ESR line-width anisotropy and the antiferromagnetic-resonance modes allows us to single out the Dzyaloshinsky-Moriya (DM) interaction as the leading magnetic anisotropy term. We demonstrate that the rather minute out-of-plane DM component $d_c=45$ mK is responsible for selecting a unique ground state, which endures thermal fluctuations up to astonishingly high temperatures. 
A. Zorko, M. Pregelj, A. Poto\v{c}nik, J. van Tol, A. Ozarowski, V.   Simonet, P. Lejay, S. Petit, and R. Ballou
cond-mat.str-el