Two-dimensional system of strongly interacting electrons in silicon (100) structures
Institute of Solid-State Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region, Russian Federation
The aim of the review is to describe and critically analyze the work of various experimental groups that studied the properties of a two-dimensional electron gas in silicon semiconductor systems ( (100) Si-MOSFET and (100) SiGe / Si / SiGe quantum wells) in the vicinity
of the metal-insulator transition. The results are general for all researchers: (i) the effective mass of electrons measured at the Fermi level in the metalic region increases with decreasing concentration and, by extrapolation, tends to divergence; (ii) the average mass in the metalic region behaves differently in the two systems studied: in Si-MOSFET , it also shows a tendency to divergence, in the SiGe / Si / SiGe quantum wells — saturates in the region of minimum concentrations; (iii) in the metallic phase, there is a small (depending on the quality of the sample) amount of localized electrons; (iv) in the insulator phase, in the vicinity of the metal-insulator transition, the electron system exhibits properties typical of amorphous media with a strong interaction between particles.
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