Phase separation in the two-dimensional electron liquid in MOSFET's

We show that the existence of an intermediate phase between the Fermi-liquid and the Wigner crystal phases is a generic property of the two-dimensional pure electron liquid in MOSFET's at zero temperature. The physical reason for the existence of these phases is a partial separation of the uniform phases. We discuss properties of these phases and a possible explanation of experimental results on transport properties of low-density electron gas in Si MOSFET's. We also argue that in a certain range of parameters, the partial phase separation corresponds to a supersolid phase discussed in F. Andreev and I. M. Lifshitz [Sov. Phys. JETP 48, 1107 (1969)].