High-fidelity projective readout of a solid-state spin quantum register

Understand

Initialization and readout of coupled quantum systems are essential ingredients for the implementation of quantum algorithms.

• If the state of a multi-qubit register can be read out in a single shot, this enables further key resources such as quantum error correction and deterministic quantum teleportation, as well as direct investigation of quantum correlations (entanglement).
• While spins in solids are attractive candidates for scalable quantum information processing, thus far single-shot detection has only been achieved for isolated qubits.
• Here, we demonstrate preparation and measurement of a multi-spin quantum register by implementing resonant optical excitation techniques originally developed in atomic physics.