Spin polarization and metallic behavior of a silicon two-dimensional electron system

TL;DR

This study investigates the magnetic and transport properties of a silicon-based two-dimensional electron system, revealing linear spin polarization increase, persistent metallic behavior under magnetic fields, and magnetoresistance anisotropy.

Contribution

It provides new insights into spin polarization, susceptibility, and anisotropic magnetoresistance in ultra-low-resistivity Si/SiGe quantum wells.

Findings

Spin polarization increases linearly with magnetic field.

Metallic behavior persists even in strong magnetic fields.

Magnetoresistance anisotropy depends on the angle between current and magnetic field.

Abstract

We have studied the magnetic and transport properties of an ultra-low-resistivity two-dimensional electron system in a Si/SiGe quantum well. The spin polarization increases linearly with the in-plane magnetic field and the enhancement of the spin susceptibility is consistent with that in Si-MOS structures. Temperature dependence of resistivity remains metallic even in strong magnetic fields where the spin degree of freedom is frozen out. We also found a magnetoresistance anisotropy with respect to an angle between the current and the in-plane magnetic field.