A high-resolution molecular spin-photon interface at telecommunications wavelengths

TL;DR

This paper introduces a molecular spin-photon interface using organo-erbium that operates at telecommunications wavelengths, enabling high-resolution optical control and readout of spin states for scalable quantum technologies.

Contribution

It presents a novel organo-erbium spin qubit with MHz-scale optical and spin transitions, facilitating high-resolution spin access at telecom wavelengths.

Findings

Achieved optical spin polarization and readout distinguishing spin states.

Demonstrated coupling of narrow optical and spin transitions at telecom frequencies.

Enabled potential integration with existing photonic and microwave devices.

Abstract

Optically addressable electronic spins in polyatomic molecules are a promising platform for quantum information science with the potential to enable scalable qubit design and integration through atomistic tunability and nanoscale localization. However, optical state- and site-selection are an open challenge. Here we introduce an organo-erbium spin qubit in which narrow (MHz-scale) optical and spin transitions couple to provide high-resolution access to spin degrees of freedom with telecommunications frequency light. This spin-photon interface enables demonstration of optical spin polarization and readout that distinguishes between spin states and magnetically inequivalent sites in a molecular crystal. Operation at frequencies compatible with mature photonic and microwave devices opens a path for engineering scalable, integrated molecular spin-optical quantum technologies.