Interaction-Induced Transition at Low Densities in Silicon Inversion Layer

Intravalley exchange and correlation are found to induce a first-order transition at low densities in the inversion layer, lowering the valley degeneracy. For the n channel on Si(100) surface, the reduction from two valleys to one occurs roughly below 3×{}10¹¹ cm^-2. The one-valley phase with domain structure yields activated conductivity and other observed low-density behavior.