Shear wave attenuation in smectic-A liquid crystals

Abstract
We have studied the shear impedance of two smectics-A when the propagation of the shear wave is along the normal to the layers. We observed that the real part and the imaginary part of the shear impedance differ significantly, indicating a relaxation process. We analysed our results on the basis of a coupling between the director fluctuations and the shear flow