T centers in silicon: an emerging platform as a spin-photon interface

ABSTRACT

Silicon is a leading platform for scalable integrated photonics and a high-quality host for solid-state spins, yet realizing an efficient spin–photon interface remains challenging. I will present an integrated photonic platform based on T centers—carbon-hydrogen defects in silicon—operating in the telecom O-band with long spin coherence times. We integrate T centers into photonic crystal cavity (PCC) arrays coupled to a bus waveguide, enabling wavelength-multiplexed emission and revealing cavity–cavity interactions. This architecture supports high-bandwidth entanglement and allows us to identify laser-induced spectral diffusion as the dominant source of linewidth broadening. Finally, I will discuss coherent control and optical readout of electron and nuclear spins, including entanglement among an electron and two nearby nuclear spins, demonstrating a three-spin quantum register. These results mark key steps toward scalable silicon-based quantum networks.

BIOGRAPHY

Xueyue (Sherry) Zhang is an Assistant Professor of Applied Physics at Columbia University. She earned her B.Eng. from Tsinghua University and her Ph.D. in Applied Physics from Caltech, followed by a Postdoc training at UC Berkeley. Dr. Zhang's research interests include superconducting circuits, quantum many-body simulations, and color centers in silicon. Her work has earned her several awards, including the Miller Postdoc Fellowship, the Boeing Quantum Creator Prize, and the Rising Star in Physics.