Optimal quantum control of Si/SiGe spin qubits in a Quantum bus architecture

Quantum bus architecture based on electron spin-shuttling is a promising candidate for scalable quantum computing, as the number of control lines required to control the spin remains constant irrespective of the length of the device. A gated Si/SiGe quantum well with a carefully placed micro- magnet acts as an addressable qubit system in such an architecture. We investigate the feasibility of performing single qubit operations using optimal quantum control techniques. Spin decoherence due to interaction with the valley degree of freedom in the Si/SiGe heterostructure is identified as a potential decay mechanism and optimal pulses are engineered to maximize single qubit state transfer and unitary operation fidelities, so that the operations are compliant with the fault tolerant error threshold.