Resonant x-ray scattering study of the URu_2Si_2 hidden-order phase

摘要

Resonant x-ray scattering experiments have been performed on a high-quality single crystal of URu_2Si_2, cut with a [101] direction specular. Data have been collected at the uranium M_4 absorption edge below the hidden-order transition temperature, T_h = 17.5 K, exploring the region of the reciprocal space plane [HOL] with 1 ≤H≤1.85 and 1.8 ≤ L≤ 2.1. Within the sensitivity of our measurements, the results obtained exclude electric quadrupoles of any symmetry as a hidden-order parameter with a propagation vector in the explored region.