Nature of the Metal Insulator Transition in High-Mobility 2D_Si-MOSFETs

Our investigation focuses on the analysis of the conductive properties of high-mobility 2D-Si-MOSFETs as they approach the critical carrier density, n(sc) (approximately 0.72 x 10(11) cm(-2)), which marks the metal insulator transition (MIT). In close proximity to the n(sc), the conductivity exhibits a linear dependence on the temperature (T). By examining the extrapolated conductivity at the absolute zero temperature (T = 0), denoted as s(0), as a function of the electron density n(s), we identify two distinct regimes with varying s(0)(n(s)) patterns, indicating the existence of two different phases. The transition from one of these two regimes to another, coinciding with n(sc), is abrupt and serves as the focus of our investigation. Our aim is to establish the possibility of a percolation type transition in the 2D-Si-MOSFETs' sample. In fact, we observed that the model of percolation is applicable only for densities very close to n(sc)*=n(2) (where n(2) is the linear extrapolation of s(0)), indicating the percolation type transition essentially represents a phase transition at the zero temperature.