"Tunable light drag effects in Cu2O"

We develop a general theory of the Fresnel light drag for nonstationary boundaries and one in which frequency and angular dispersion of the dragging medium are both included. We apply the theory to investigate a Fizeau-type optical interferometer that uses coherently driven cuprous oxide (Cu(2)O) as dragging medium. For such a material, where electromagnetically induced transparency can be implemented through a typical pump-probe configuration, the resonant probe-beam experiences a phase shift (Fresnel-Fizeau effect) that may vary over a wide range of values, positive or negative, or it may even vanish due to the combined effects of the strong frequency dispersion and anisotropy both induced by the pump. Our drag values are compared with those obtained by using standard dragging materials as well as with those where neutron rather than light waves are being dragged. The similarities between matter and light waves yield essential insights into the nature of the dragging effect with massive and massless particles.