Quantum mechanics of a solid-state bar gravitational antenna

A quantum-mechanical treatment of a bar gravitational antenna is presented. The theory takes into account the crystalline structure of the bar and collective behavior of its mass elements. The low-frequency and high-frequency (Debye) modes of oscillations are considered. It is shown that the quantum-mechanial derivation of the absorption cross section of the gravitational antenna agrees totally with the classical result. The recent claims of a significant (six orders of magnitude) quantum-mechanical enhancement of the cross section are shown to be incorrect.