Ultrasonic attenuation via energy diffusion channel in disordered conductors

TL;DR

This paper predicts a new energy diffusion channel causing ultrasound attenuation in disordered conductors and superconductors, with significant enhancement in materials like doped silicon and BSCCO, especially near the BCS-BEC crossover.

Contribution

It introduces a novel dissipation mechanism due to thermal energy diffusion affecting ultrasound attenuation in disordered systems.

Findings

Ultrasound attenuation can be enhanced by a factor of about 100 in doped silicon.

Strong attenuation effects are predicted for BSCCO superconductors.

The new channel is relevant for low-electron-density materials near the BCS-BEC crossover.

Abstract

We predict an existence of an new dissipation channel leading to attenuation of ultrasound in disordered conductors and superconductors with perfect electroneutrality. It is due to slow diffusion of thermal energy. We show that in doped silicon ultrasound attenuation may be enhanced by a factor about 100. Similar effect is also studied for s-wave and d-wave superconductors. The latter case is applied to BSCCO family where strong enhancement of ultrasound attenuation is predicted. For usual s-wave superconductors new dissipation channel might be important for very low-electron-density materials near the BCS-BEC crossover.