Carrier and Spin Coherent Dynamics in Strained Germanium-Tin Semiconductor on Silicon

TL;DR

This paper demonstrates optical control and measurement of spin dynamics in strained germanium-tin semiconductors on silicon, revealing robust spin properties and potential for spintronics and photonics applications.

Contribution

It provides the first demonstration of optical spin initialization and readout in GeSn alloys on silicon, highlighting their promising spintronic and photonic functionalities.

Findings

Robust spin orientation over a wide temperature range

Persistent spin lifetime approaching nanoseconds at room temperature

Observation of spin quantum beats under magnetic field

Abstract

Germanium-Tin is emerging as a material exhibiting excellent photonic properties. Here we demonstrate optical initialization and readout of spins in this intriguing group IV semiconductor alloy and report on spin quantum beats between Zeeman-split levels under an external magnetic field. Our optical experiments reveal robust spin orientation in a wide temperature range and a persistent spin lifetime that approaches the ns regime at room temperature. Besides important insights into nonradiative recombination pathways, our findings disclose a rich spin physics in novel epitaxial structures directly grown on a conventional Si substrate. This introduces a viable route towards the synergic enrichment of the group IV semiconductor toolbox with advanced spintronics and photonic capabilities.