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/Si_{1-x}Ge_x heterostructure with mobility μ=1.9 x 10^5 cm^2/Vs at density n=1.45 x 10^{11} cm^{-2}. The critical density, at which the thermal coefficient of low T resistivity changes sign, is ~ 0.32 x 10^{11} 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 ~ B_{ip}^2 and then saturates to a finite value ρ(B_c) for B_{ip} > B_c. The full spin-polarization field B_c decreases monotonically with n but appears to saturate to a finite value as n approaches zero. Furthermore, ρ(B_c)/ρ(0) ~ 1.8 for all the densities ranging from 0.35 x 10^{11} to 1.45 x 10^{11} cm^{-2} and, when plotted versus B_{ip}/B_c, collapses onto a single curve.

References in corpus (4)

• Metal-insulator transition in two-dimensional electron systems
• The Two-flux Composite Fermion Series of Fractional Quantum Hall States in Strained Si
• Spin and Valley dependent analysis of the two-dimensional low-density electron system in Si-MOSFETS
• Remote-doping scattering and the local field corrections in the 2D electron system in a modulation-doped Si/SiGe quantum well

Cited by in corpus (10)

• The Observation of Percolation-Induced 2D Metal-Insulator Transition in a Si MOSFET
• Transport and percolation in a low-density high-mobility two-dimensional hole system
• Valley polarization assisted spin polarization in two dimensions
• Fractional Quantum Hall Effect in a Diluted Magnetic Semiconductor
• Linear temperature dependence of conductivity in Si two-dimensional electrons near the apparent metal-to-insulator transition
• Novel Energy Scale in the Interacting 2D Electron System Evidenced from Transport and Thermodynamic Measurements
• Unusual anisotropy of inplane field magnetoresistance in ultra-high mobility SiGe/Si/SiGe quantum wells
• Modulation of the high mobility two-dimensional electrons in Si/SiGe using atomic-layer-deposited gate dielectric
• Conductivity of a spin-polarized two-dimensional electron liquid in the ballistic regime
• Universal transport at Lifshitz metal-insulator transitions in two dimensions