Quantum Beats in Time Resolved X-Ray Interference Experiments

Abstract

We have employed LLL-type X-ray interferometers with a splitted mirror crystal and quartz crystals attached aside each mirror. Ultrasound waves of different frequencies f 1 and f 2 around 10 MHz are fed into these mirrors. The ultrasound modulations of the coherently splitted X-ray beams inside the interferometer are analysed in time resolved interference experiments correlating the phase of the phonons with the registration time of the photons. In the interference intensity we observe quantum beat frequencies down to Df = 96 mHz (in energy scale DE = h Df = 397 atto-eV) as well as the two ultrasound frequencies and their overtones mf 1 and nf 2 (m, n = 1, 2, 3) and the sum frequency Sf = f 1 + f 2 .