Spin qubits in silicon carbide for quantum technologies

Chris Anderson - University of Chicago

Spin qubits in silicon carbide for quantum technologies

Defect spin qubits in silicon carbide (SiC) with associated nuclear spin quantum memories can leverage near-telecom emission and wafer-scale semiconductor device engineering for creating quantum technologies. Here, I highlight recent advances with the neutral divacancy defect (VV0) in SiC within the context of long-distance quantum communication and repeater schemes. Broadly, I will illustrate how quantum states can be controlled, tuned, and enhanced through their integration into SiC mechanical, photonic, and electrical devices. I will first describe the isolation of single VV0 defects in functional SiC optoelectronic devices, which allows for deterministic charge state control and terahertz tuning, but also surprisingly eliminates spectral diffusion in the optical structure of these defects. I will then discuss the entanglement and control of nuclear spin registers, and show how isotopic engineering can enhance both nuclear quantum memories and electron spin coherence times, while also demonstrating high fidelity control (99.98%), initialization, and readout. Briefly, I will further highlight recent results that universally protect spin coherence from electrical, magnetic, and thermal noise, resulting in T2* ＞ 20 ms in a naturally abundant crystal. This suite of results establishes SiC as a promising platform for scalable quantum science with optically-active spins.