Electrically detected magnetic resonance of neutral donors interacting with a two-dimensional electron gas

TL;DR

This study investigates electrically detected magnetic resonance of silicon donors interacting with a 2D electron gas at different microwave frequencies, revealing a polarization transfer mechanism as the main cause of the observed signals.

Contribution

It introduces a new polarization transfer model explaining the magnetic resonance signals in silicon donors interacting with a 2D electron gas, challenging previous scattering-based explanations.

Findings

Resonance signals increase significantly from X- to W-band frequencies.

Hyperfine-split donor signals are enhanced over tenfold at higher frequencies.

A new polarization transfer mechanism is proposed as the primary cause of the signals.

Abstract

We have measured the electrically detected magnetic resonance of channel-implanted donors in silicon field-effect transistors in resonant X- ($9.7\:$GHz) and W-band ($94\:$GHz) microwave cavities, with corresponding Zeeman fields of $0.35\:$T and $3.36\:$T, respectively. It is found that the conduction electron resonance signal increases by two orders of magnitude from X- to W-band, while the hyperfine-split donor resonance signals are enhanced by over one order of magnitude. We rule out a bolometric origin of the resonance signals, and find that direct spin-dependent scattering between the two-dimensional electron gas and neutral donors is inconsistent with the experimental observations. We propose a new polarization transfer model from the donor to the conduction electrons as the main contributer to the spin resonance signals observed.