Metal-Insulator Transition and Spin Degree of Freedom in Silicon 2D Electron Systems

TL;DR

This paper investigates the metal-insulator transition and the role of electron spin in silicon-based 2D electron systems, revealing persistent metallic behavior under high magnetic fields and exploring spin polarization effects.

Contribution

It provides new experimental insights into how spin polarization influences metallicity and resistivity in silicon 2D electron systems under strong magnetic fields.

Findings

Metallic behavior persists in Si/SiGe systems even at 9T magnetic field.

Resistivity minima correlate with spin polarization states.

Spin degree of freedom significantly affects transport properties.

Abstract

Magnetotransport in 2DES's formed in Si-MOSFET's and Si/SiGe quantum wells at low temperatures is reported. Metallic temperature dependence of resistivity is observed for the n-Si/SiGe sample even in a parallel magnetic field of 9T, where the spins of electrons are expected to be polarized completely. Correlation between the spin polarization and minima in the diagonal resistivity observed by rotating the samples for various total strength of the magnetic field is also investigated.