Interconnected Spin Chains for Scalable Quantum Simulators

Objective

Quantum simulation using qubits offers methods to modeling systems intractable for classical computation. Among many spin qubits, silicon vacancies (V2) in silicon carbide (SiC) stand out for their lifetime-limited linewidth in nanostrucutres, scalable foundry-ready fabrication, and potentials for CMOS compatibility. While recent works showed the potential to map a network of 50 coupled spins around a single color center, this method reached its scaling limit. Next step is to couple multiple color centers, but it presents a significant challenge from signal crowding and overlap. This project addresses this bottleneck by developing a hybrid device. It is designed to provide multi-dimensional tuning (via Stark, strain, and magnetic field), enabling site-selective control and individual addressing of multiple color centers. I will exploit mature silicon nitride (Si3N4) platform for tuning electrodes and photonic circuits, then heterogeneously integrate defect-containing SiC structures on. This architecture will retain color center performance, provide targeted control, diminish noises, and enhance signal collection, thereby realizing an interconnected spin chain system scalable of 1000s of spins. The project will proceed in three key stages. First, I will conduct a theoretical optimization study of the device. Next, I will fabricate a heterogeneous Si3N4/SiC device. Finally, I will demonstrate the formation of interconnected spin chains by tuning multiple color centers to distinct frequencies, then measuring their coupling matrix and many-spin dynamics. This research will accelerate quantum simulations with unprecedented number of qubits. I will leverage my expertise in photonics, fabrication, electrical and cryogenic engineering and collaborate with leading and interdisciplinary experts in both of my host groups at QuTech. This fellowship will enhance my scientific and transferable skills, foster pioneering work in quantum simulation and enable further collaborations.