Transition from a fractional quantum Hall liquid to an electron solid at Landau level filling nu=1/3 in tilted magnetic fields

We have observed in a low density two-dimensional hole system (2DHS) of extremely high quality (with hole density p=1.6x10(10) cm(-2) and mobility mu=0.8x10(6) cm(2)/V s) that, as the 2DHS is continuously tilted with respect to the direction of the magnetic field, the nu=1/3 fractional quantum Hall effect (FQHE) state is weakened and at the temperature of similar to30 mK its magnetoresistivity rises from similar to0.4 kOmega/square in the normal orientation to similar to180 kOmega/square at tilt angle thetasimilar to80degrees. We attribute this phenomenon to the transition from the FQHE liquid state to the pinned Wigner solid state, and argue that its origin is the strong coupling of subband Landau levels under the tilted magnetic fields.