A coherent spin-photon interface with waveguide induced cycling transitions

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 ≈ 15 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.

High-fidelity multi-photon-entangled cluster state with solid-state quantum emitters in photonic nanostructures

“…[32] using a micropillar cavity system, however, without the interferometric measurements needed to prove entanglement. The use of a PCW in our scheme offers several important advantages needed for efficient scaling [33]: (i) the singlephoton coupling efficiency to the waveguide can be near-unity, (ii) the photon indistinguishability can be enhanced by the Purcell effect, and (iii) the generally high coupling asymmetry of the two in-plane linear dipole transitions imply that highquality optical cyclings can be induced on the designated transition while still allowing optical spin rotations [47]. In the following, we account for all experimental imperfections and evaluate the fidelity of multi-photon GHZ and cluster states.…”