We report on experiments using energetic ultrasound pulses on superfluid 3He-B. Near the two-phonon pair breaking edge, at hf=Δ(T), an anomaly in ultrasonic attenuation has been detected. This feature grows with increasing acoustical intensity, and a new peak develops in the attenuation spectrum. The anomaly, coupling nonlinearly to ultrasound, can be observed also in the phase velocity of sound; in a magnetic field the anomaly splits to at least three features.
|Number of pages||2|
|Journal||Physica B: Physics of Condensed Matter|
|Issue number||PART 1|
|Publication status||Published - 2 Feb 1994|
|MoE publication type||A1 Journal article-refereed|