Spin-Polarized Transient Electron Trapping in Phosphorus-doped Silicon

TL;DR

This study investigates spin precession in phosphorus-doped silicon, revealing two distinct electron trapping and transport processes, and highlights implications for quantum information science.

Contribution

It provides experimental evidence of spin dynamics involving impurity traps and metastable states, advancing understanding of spin transport at the quantum level.

Findings

Identification of short conduction-band transport times (~50ps)

Observation of long trapping-related times (~1ns)

Demonstration of impurity state participation in spin dynamics

Abstract

Experimental evidence of electron spin precession during travel through the phosphorus-doped Si channel of an all-electrical device simultaneously indicates two distinct processes: (i) short timescales (~50ps) due to purely conduction-band transport from injector to detector, and (ii) long timescales (~1ns) originating from delays associated with capture/re-emission in shallow impurity traps. The origin of this phenomenon, examined via temperature, voltage, and electron density dependence measurements, is established by means of comparison to a numerical model and is shown to reveal the participation of metastable excited states in the phosphorus impurity spectrum. This work therefore demonstrates the potential to make the study of macroscopic spin transport relevant to the quantum regime of individual spin interactions with impurities as envisioned for quantum information applications.