Transverse Acoustic Impedance Measurements for Surface States of Superfluid 3He A1 and A2 Phases

We measured the complex transverse acoustic impedance in both superfluid 3 He A 1 and A 2 phases. This impedance is sensitive to surface states. In our preliminary results, the temperature dependence of the impedance in the A 1 phase is similar to that in A phase, and the imaginary part shows an anomaly in the A 2 phase. These anomalies occurred at the temperature defined as T k , which is lower as the frequency gets higher. The similar frequency dependence of T k in each phase suggests that the anomaly is attributed to the same origin. The frequency dependence of the T k / T c indicates that the shape of the surface density of each spin pair state did not greatly change in the present experimental temperature range.