Chiral criticality in helimagnet Ho studied by polarized neutron scattering -: art. no. 100402

The critical exponents for the average chirality, beta (c) = 0.90(3), and the chiral susceptibility, gamma (c) = 0.68(6), are determined for the spin-ordering transition in helimagnet Ho. The beta (c) is extraordinarily large and twice higher than the predicted value for the chiral universality class, while the gamma (c) is in agreement with this scenario. The staggered magnetization critical exponent is determined to be beta =0.38(1). The difference beta (c)-2 beta = 0.137(36) suggests that chirality is a component of the order parameter independent of the staggered magnetization. The chiral-ordering transition and the Neel temperature coincide with a relative precision of 10(-4).