Melting of Two-Dimensional Electron Crystal on Liquid 3He Induced by Resonance Microwave Absorption

Microwave-resonance induced increase of magneto-resistivity σ _xx ⁻¹ of the surface-state electrons (SSE) on liquid ³He is observed at low temperatures at which SSE crystallize into the Wigner solid (WS). At the resonance, the relative change of σ _xx ⁻¹ of SSE in the solid phase is found to be several times of the corresponding change in the liquid phase measured under similar experimental conditions. We attribute this effect to melting of WS induced by electron heating which accompanies the microwave absorption. σ _xx ⁻¹ is found to increase gradually with microwave power, which is rather different from the sharp resistivity increase induced by direct heating of the substrate in the absence of microwaves. The effect of microwave resonance-induced heating on the sliding of WS from the periodic surface deformation of liquid is also investigated.