Ultrasonic attenuation in a pseudogapped superconductor

Abstract

We develop a theory of ultrasound decay rate $\alpha$ in a model of a superconductor with a large pseudogap ${\Delta }_P$, and show that at low temperatures ($T\ll T_c$) the magnitude of the decay rate $\alpha$ is controlled by the ratio of $T/\Delta$, where $\Delta \ll {\Delta }_P$ is a superconducting collective gap. Thus we propose new method to measure the collective gap $\Delta$ in a situation when strong pseudogap is present.

7 pages