A Coherent Spin-Photon Interface in Silicon

TL;DR

This paper demonstrates a strong coherent interaction between a single silicon spin and microwave photons, enabling long-distance qubit coupling and advancing silicon-based quantum computing.

Contribution

It introduces a novel silicon spin-photon interface with strong coupling and coherent control, facilitating scalable quantum networks.

Findings

Achieved spin-photon coupling rates >10 MHz

Demonstrated coherent control and spin state readout

Enabled potential for long-distance spin entanglement

Abstract

Electron spins in silicon quantum dots are attractive systems for quantum computing due to their long coherence times and the promise of rapid scaling using semiconductor fabrication techniques. While nearest neighbor exchange coupling of two spins has been demonstrated, the interaction of spins via microwave frequency photons could enable long distance spin-spin coupling and "all-to-all" qubit connectivity. Here we demonstrate strong-coupling between a single spin in silicon and a microwave frequency photon with spin-photon coupling rates g_s/(2\pi) > 10 MHz. The mechanism enabling coherent spin-photon interactions is based on spin-charge hybridization in the presence of a magnetic field gradient. In addition to spin-photon coupling, we demonstrate coherent control of a single spin in the device and quantum non-demolition spin state readout using cavity photons. These results open a direct path toward entangling single spins using microwave frequency photons.