A coherent spin-photon interface with waveguide induced cycling transitions

TL;DR

This paper demonstrates a solid-state quantum dot spin-photon interface with enhanced cyclicity and control using a photonic crystal waveguide, enabling scalable quantum information processing.

Contribution

It introduces a novel waveguide-induced cycling transition in quantum dots, improving optical cyclicity and spin control capabilities.

Findings

Achieved optical cyclicity up to approximately 15.

Demonstrated high-fidelity spin initialization.

Enabled coherent optical spin control.

Abstract

Solid-state quantum dots are promising candidates for efficient light-matter interfaces connecting internal spin degrees of freedom to the states of emitted photons. However, selection rules prevent the combination of efficient spin control and optical cyclicity in this platform. By utilizing a photonic crystal waveguide we here experimentally demonstrate optical cyclicity up to $\approx15$ through photonic state engineering while achieving high fidelity spin initialization and coherent optical spin control. These capabilities pave the way towards scalable multi-photon entanglement generation and on-chip spin-photon gates.