STUDY ON SUPERFLUID ^3He FILMS-THIRD SOUND AND 2D ELECTRONS-

这是用二维电子作为探针对超流体^3He薄膜的研究，并寻找第三种声音。通过将静电电位作用于互指电极，驱动了^3He薄膜，并成功地观察了^3He超流体中的薄膜流动。研究发现，在电极上，部分膜失去了体液与膜之间的超流动性。我们准备了包含ID电极垂直的电池，因此在散装液体和薄膜之间没有边缘，并且正在计划系统的测量。虽然计划利用ID电极探测波长为10μm的第三声，但未能观测到信号。这可归因于准粒子在自由表面散射造成的大的第三声阻尼。因此，我们正在开发一种技术，采用双锁定技术，激发长波第三声。到目前为止，使用^4He的检查已成功完成。在体^3He上研究了二维电子，我们了解到在薄膜上有许多可能的实验。观察维格纳固体的量子熔化可能是最重要的课题之一。

This is a study of superfluid ^3He films by means of 2D electrons as a probe, and a search for third sound.By applying electrostatic potential to interdigitated (ID) electrodes, we drove ^3He films and successfully observed the film flow in superfluid ^3He. It was found that certain part of the film lost the superfluidity between bulk liquid and the film on the ID electrodes. We prepared the cell which contained the ID electrodes vertical, and hence there is no edge between bulk liquid and the film, and are palnning a systematic measurement.Although it was intended to detect third sound of the wavelength of 10μm by use of the ID electrodes, it was not able to observe the signal. It can be attributed to large damping of third sound caused by quasiparticle scattering at free surface. Therefore, we are developing a technique, employing the double lock-in technique, to excite long wavelength third sound. So far, a check using ^4He was successfully done.2D electrons are studied on bulk ^3He, we learned that there were many possible experiment on the film. The observation of quantum melting of the Wigner solid may be one of the most important topics.