Magnetic fields for protecting Silicon T-center nuclear qubits from a hyperfine interaction

Synopsis

Measurement-based quantum computation relies upon measuring an array of qubits that begin in a highly-entangled state, known as a graph state. To prepare this entanglement resource, a brokered approach may be deployed: one qubit, such as an electron spin, acts as a broker to generate new entanglement between lattice points, while another qubit, such as a nuclear spin, acts as a client to store previously constructed graph fragments. Such fragments are susceptible to corruption if the broker and client interact with each other during inter-broker entanglement operations. The Silicon Quantum Technology group at SFU hopes to perform quantum computation using electron and nuclear spins that belong to a silicon defect center known as the T center. To construct graph states across T centers, the nuclear spin must remain isolated from the electron spin during optical excitations. In this talk I will discuss how applying magnetic fields along special directions can protect the nuclear spin from its anisotropic hyperfine interaction with the electron spin, and the implications for generating graph states.