FREE SURFACE OF FERMI LIQUID

我们测量了维格纳固体在正常和超流氦-3上的电导率，并给出了理论解释。维格纳体是一种三角形点阵的二维晶体，每个点阵下都有微坑。当微坑移动时，它在液态氦-a3中散射准粒子，并感受到摩擦力。当温度较高（> 100 mK）时，准粒子间的散射平均自由程很短，使得液体表现为经典粘性液体。随着温度的降低，费米液体的粘度与T^2成正比地增加，因此电导率也随之降低。随着温度的降低，平均自由程增大，超过了Wigner固体的晶格常数，电导率对温度不再敏感。进一步降低到较低的温度，最终氦-3经历了超流性转变，这导致了液态氦-3的激发光谱的变化。这种变化自然会干扰实验观测，目前的研究仅限于超流氦-3的B相。有必要将目前的工作扩展到具有各向异性能隙的A相。

We measured the conductivity of the Wigner solid on normal-and superfluid helium-3 and gave a theoretical account. The Wigner solid is a two-dimensioanlcrystal of triangular lattice, which is accompanied with dimples under each lattiec site. When the dimple moves, it scatters quasiparticles in liquid helium-a3 and feels the frictional force. With calculating this force quantitatively, one can account for the behavior of the conductivity.When temperature is high (>100mK), the scattering mean free path between quasiparticles is so short that the liquid behaves as if a classical viscous liquid. The viscosity of the Fermi liquid increases proportional to T^2, as temperature decreases, and hence the conductivity decreases. Decreasing temperature, the mean free path incereases longer than the lattice constant of the Wigner solid, so that the conductivity becomes no more sensitive to the temperature. Going further down to lower temperature, eventually helium-3 undergoes the superfluidity transition, which casses a change in the excitation spectrum of liquid helium-3. This change can naturally interplete the experimental observation.The present research is restricted in the B-phase of superfluid helium-3. It is necessary to extend the present work to A-phase, which has an anisotropic energy gap.