Excited state dynamics of integrated silicon colour centres

Quantum repeaters offer a promising solution to overcome losses in quantum networks and extend their reach. The T centre, a silicon colour centre, has emerged as a compelling platform for quantum repeaters and networked quantum computing, owing to its spin-selective optical transitions in the telecommunications O-band, long-lived solid-state spin qubits, and compatibility with silicon photonic circuits.

A reliable spin-photon interface must overcome several challenges, including the crucial need for optical excitation that is both cyclic and spectrally stable. We investigate commercial on-chip devices hosting cavity-coupled T centres to study the excited state dynamics that can degrade cyclicity and the causes of spectral wandering. We will discuss mitigation strategies for both. Finally, we outline the key elements necessary for generating large, highly entangled photonic tree cluster states in T centre on-chip devices for one-way photonic quantum repeaters.