Short-range correlations in quantum frustrated spin system

We report on results of sound-velocity and sound-attenuation measurements in the low-dimensional spin-1/2 antiferromagnet Cs₂CuCl₄ (T_N = 0.6 K), in external magnetic fields up to 15 T, applied along the b axis, and at temperatures down to 300 mK. The experimental data are analyzed with a theory based on exchange-striction coupling resulting in a qualitative agreement between theoretical results and experimental data.