Local Spin Susceptibilities of Low-Dimensional Electron Systems

TL;DR

This paper proposes a method to measure local spin susceptibilities in low-dimensional electron systems using a source-probe setup with magnetic detection, highlighting feasibility in 1D systems and potential in 2D systems with suitable materials.

Contribution

It introduces a novel experimental approach to measure local spin susceptibilities in low-dimensional systems, detailing the setup and feasibility considerations.

Findings

One-dimensional systems like nanowires are detectable.

Two-dimensional systems have weaker signals but are still measurable with high g-factor materials.

The proposed method enables spatial mapping of spin susceptibility.

Abstract

We investigate, assess, and suggest possibilities for a measurement of the local spin susceptibility of a conducting low-dimensional electron system. The basic setup of the experiment we envisage is a source-probe one. Locally induced spin density (e.g. by a magnetized atomic force microscope tip) extends in the medium according to its spin susceptibility. The induced magnetization can be detected as a dipolar magnetic field, for instance, by an ultra-sensitive nitrogen-vacancy center based detector, from which the spatial structure of the spin susceptibility can be deduced. We find that one-dimensional systems, such as semiconducting nanowires or carbon nanotubes, are expected to yield a measurable signal. The signal in a two-dimensional electron gas is weaker, though materials with high enough $g$-factor (such as InGaAs) seem promising for successful measurements.