Hopping in Si-MOSFETs near the 2D metal–insulator transition

We investigated the temperature dependence of resistivity of a high mobility Si-MOSFET in the insulating regime near a 2D metal–insulator transition. Coulomb hopping in a wide range of temperature and carrier density was found. Quantitative analysis of the results suggests that electron–electron interaction is screened by the metal-gate as the localization length increases. The hopping is highly correlated, i.e. the observed hopping energy is one order of magnitude smaller than the expected value from a single-particle hopping picture.