Vm. Pudalov et St. Chui, CHARACTER OF THE PHASE-TRANSITION AT THE 2-DIMENSIONAL ELECTRON LIQUID-TO-SOLID BOUNDARY, Physical review. B, Condensed matter, 49(19), 1994, pp. 14062-14065
Nonlinear threshold electric transport has been studied at T congruent
-to 30 mK near the collective insulating transition in a dilute two-di
mensional (2D) electron system in high-mobility Si MOSFET's. We found
that the threshold electric field becomes steplike at the critical den
sity, both when H = 0 and when H not-equal 0. This steplike onset indi
cates a weak first-order phase transition at the 2D electron-solid-to-
liquid phase boundary.