Two-dimensional metal-insulator transition and in-plane magnetoresistance in a high mobility strained Si quantum well
Abstract
The apparent metal-insulator transition is observed in a high quality two-dimensional electron system (2DES) in the strained Si quantum well of a Si/Si1-xGex heterostructure with mobility μ=1.9 x 105 cm2/Vs at density n=1.45 x 1011 cm-2. The critical density, at which the thermal coefficient of low T resistivity changes sign, is ~ 0.32 x 1011 cm-2, so far the lowest observed in the Si 2D systems. In-plane magnetoresistance study was carried out in the higher density range where the 2DES shows the metallic-like behavior. It is observed that the in-plane magnetoresistance first increases as ~ Bip2 and then saturates to a finite value ρ(Bc) for Bip > Bc. The full spin-polarization field Bc decreases monotonically with n but appears to saturate to a finite value as n approaches zero. Furthermore, ρ(Bc)/ρ(0) ~ 1.8 for all the densities ranging from 0.35 x 1011 to 1.45 x 1011 cm-2 and, when plotted versus Bip/Bc, collapses onto a single curve.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.