Abstract: A scalable point defect qubit control system may include a diamond waveguide array comprising one or more diamond waveguides and a microwave line disposed proximally to the diamond waveguide array. Each diamond waveguide in the diamond waveguide array may include one or more qubits encoded in point defect sites. The microwave line may be configured to receive a direct current (DC) signal configured to shift an energy level of each point defect qubit of the one or more point defect qubits based on a position of the point defect in the diamond waveguide array, and receive an alternating current (AC) signal configured to control a quantum state of a point defect qubit of the one or more point defect qubits, wherein one or more properties of the AC signal are based on the shift in the energy level induced by the DC signal.

Abstract: A method for controlling a qubit encoded in an atom-like defect in a solid-state host may comprise applying an electrical signal to a piezoelectric cantilever that is mechanically coupled to a photonic waveguide comprising one or more embedded point defect sites. The photonic waveguide may be optically coupled to a photonic chip. Applying the electrical signal to the piezoelectric cantilever may induce movement in the piezoelectric cantilever, which may induce a strain in the photonic waveguide. The applied electrical signal may be determined by a defect site with excitation light, measuring a frequency of a photon emitted by the excited defect site, determining a frequency shift based on the measured frequency of the emitted photon, and determining the electrical signal to be applied to the piezoelectric cantilever based on the frequency shift.