Room-Temperature Quantum Error Correction with Nitrogen-Vacancy Centers

In pursuit of near-term quantum devices that either demonstrate a `quantum supremacy’ or perform a meaningful algorithm, quantum error correction (QEC) is required. Arguably, fault-tolerance (FT) is not mandatory at this stage. Therefore, instead of traditional FT QEC, we focus on hardware-efficient QEC that demands less redundancy and imposes less overhead penalty. The system of interest is a room-temperature solid-state quantum register consisting of qubits and one ancilla, respectively given by the nuclear spins and the electronic spin associated with the NV center in diamond.
We first studied the decoherence process of the nuclear spins to better characterize the system. The errors on the nuclear spins turn out to be caused by the same source and are thus strongly correlated. We can then proceed to design custom QEC codes for this system, and develop experimental tools for realizing hardware-efficient QEC.