Coherent control of a triangular exchange-only spin qubit

Semiconductor spin qubits are a promising platform for spin-based quantum computing due to their high density and fast gate speeds. Most research to date has focused on linear quantum dot arrays with limited qubit connectivity. Scaling up these devices is desired, but the fabrication process has been an obstacle. Using a semiconductor manufacturing approach, the authors demonstrate a closely packed two-dimensional array of quantum dots with qubit fidelities exceeding 99.8%. The device architecture opens the door to fabricating larger two-dimensional quantum dot arrays with high connectivity.