Coherent Control of a Spin Qubit Register in Silicon Photonics

Color centers in silicon have recently shown their potential as telecom-band single photon emitters and long-lived quantum memories. Leveraging the mature semiconductor fabrication techniques, silicon color centers can be easily integrated into large-scale photonic circuits. Among all the silicon color centers investigated so far, the T center provides a spin-photon interface suitable for quantum networking and communication applications. Furthermore, the T center electron spin can couple to its surrounding nuclear spins, which makes individual T centers promising candidates for spin qubit registers.

In this work, we create T centers in photonic waveguides fabricated from natural silicon. We demonstrate coherent control of the electron spin of a single T center. We measure the electron spin dephasing time to be 2.63(12) μs, and extend the spin coherence time to 1.75(24) ms with dynamical decoupling. In addition, we realize coherent control of a silicon nuclear spin and a hydrogen nuclear spin coupled to the T center. We measure nuclear spin Ramsey dephasing times of 4.09(35) ms for the hydrogen nuclear spin and 14.5(11) ms for the silicon nuclear spin. We will present our progress toward entanglement generation of the two nuclear spins.