Complete state tomography of a quantum dot spin qubit

Semiconductor quantum dots are the preferred choice for interfacing anchored matter spin qubits and flying photonic qubits. They are particularly attractive for generating highly entangled hybrid spin-multiphoton entangled cluster and graph states. These highly entangled multiqubit states are required for measurement-based quantum communication and computing. Here, the authors develop a novel all-optical method for conducting full tomography of the confined electronic spin qubits. This method is essential for characterization and benchmarking these hybrid entangled spin-multiphoton cluster and graph states.