Erbium emitters in commercially fabricated nanophotonic silicon waveguides

TL;DR

This paper demonstrates the integration of erbium emitters into commercially fabricated silicon nanophotonic waveguides, achieving promising coherence properties and magnetic field effects, advancing scalable quantum memory development.

Contribution

It presents a reliable method for integrating erbium dopants into low-loss silicon waveguides with characterized optical and spin properties, suitable for scalable quantum technologies.

Findings

Inhomogeneous broadening < 2 GHz

Homogeneous linewidth < 30 kHz

Spin state splitting observed up to 9 T

Abstract

Quantum memories integrated into nanophotonic silicon devices are a promising platform for large quantum networks and scalable photonic quantum computers. In this context, erbium dopants are particularly attractive, as they combine optical transitions in the telecommunications frequency band with the potential for second-long coherence time. Here we show that these emitters can be reliably integrated into commercially fabricated low-loss waveguides. We investigate several integration procedures and obtain ensembles of many emitters with an inhomogeneous broadening of < 2 GHz and a homogeneous linewidth of < 30 kHz. We further observe the splitting of the electronic spin states in a magnetic field up to 9 T that freezes paramagnetic impurities. Our findings are an important step towards long-lived quantum memories that can be fabricated on a wafer-scale using CMOS technology.