Spin resonance of 2D electrons in a large-area silicon MOSFET

TL;DR

This study uses electron spin resonance to investigate 2D electrons at the Si/SiO2 interface in a large-area silicon MOSFET, revealing how their spin properties depend on gate voltage and confinement.

Contribution

It provides the first ESR characterization of 2D electrons in large-area silicon MOSFETs, demonstrating controllable tuning of electron spin states via gate voltage.

Findings

ESR signal at g-factor 1.9999(1) observed from 2D electrons

Signal intensity varies with gate voltage and temperature

Below threshold, electrons show Curie-like temperature dependence

Abstract

We report electron spin resonance (ESR) measurements on a large-area silicon MOSFET. An ESR signal at g-factor 1.9999(1), and with a linewidth of 0.6 G, is observed and found to arise from two-dimensional (2D) electrons at the Si/SiO2 interface. The signal and its intensity show a pronounced dependence on applied gate voltage. At gate voltages below the threshold of the MOSFET, the signal is from weakly confined, isolated electrons as evidenced by the Curie-like temperature dependence of its intensity. The situation above threshold appears more complicated. These large-area MOSFETs provide the capability to controllably tune from insulating to conducting regimes by adjusting the gate voltage while monitoring the state of the 2D electron spins spectroscopically.