WIGNER SOLID ON THE FREE-SURFACE OF SUPERFLUID HE-3

We report the measurement of electrical transport of the two-dimension al Wigner solid (WS) formed on the free surface of superfluid He-3-B d own to 230 mu K. The resistance R(T) dramatically decreases as tempera ture T decreases, obeying Arrhenius' law, R(T) proportional to exp[-De lta(T)/k(B)T], with Delta(T) which we assign to the superfluid energy gap. That is, the scattering of He-3 quasiparticles by the WS determin es the transport. The resistance depends systematically on the static electric field which presses the WS toward the liquid surface. We prop ose that the WS acts as a powerful probe for the study of the superflu id He-3.