Anomalous Spin Response in Non-centrosymmetric Compounds

Abstract

We examine static spin susceptibilities χ_αβ(q) of spin components S_α and S_β in the non-centrosymmetric tetragonal system. The anomalous susceptibility, which vanish in centrosymmetric systems, remains showing a momentum dependence like χ_xx(q)−χ_yy(q)∼q_x²−q_y² and χ_xy(q)+χ_yx(q)∼q_xq_y. A characteristic property of the non-centrosymmetric system is the non-vanishing anomalous susceptibility, whose momentum dependence is not invariant to some symmetry operations of the system. As the direct probe of the anomalous spin susceptibility, we propose a polarized neutron scattering experiment, especially, around an ordering wave vector.