Hyper-Q macroscopic oscillatory systems

Quartz-crystal oscillatory systems with a Q of 1.75 x 10 to the 10th at a temperature of 1.8 K at a frequency of 7.24 MHz have been fabricated on the basis of a technique for the preparation of a near-surface layer whose acoustic properties approach those of the bulk of the single crystal. The technique involves the physical analysis of a group of energy losses, the damping of elastic waves in defect structures of the near-surface layer of single-crystal quartz, and the transition to liquid-helium temperatures. It is noted that such oscillators can be used in gravitational-wave detection systems.