We design a logical qubit consisting of a linear array of quantum dots, we analyze error correction for this linear architecture, and we propose a sequence of experiments to demonstrate components of the logical qubit on near-term devices. To avoid the difficulty of fully controlling a two-dimensional array of dots, we adapt spin control and error correction to a one-dimensional line of silicon quantum dots. Control speed and efficiency are maintained via a scheme in which electron spin states are controlled globally using broadband microwave pulses for magnetic resonance, while two-qubit gates are provided by local electrical control of the exchange interaction between neighboring dots. Error correction with two-, three-, and four-qubit codes is adapted to a linear chain of qubits with nearest-neighbor gates. We estimate an error correction threshold of 10-4. Furthermore, we describe a sequence of experiments to validate the methods on near-term devices starting from four coupled dots.
Jones, C., Fogarty, M. A., Morello, A., Gyure, M. F., Dzurak, A. S., & Ladd, T. D. (2018). Logical Qubit in a Linear Array of Semiconductor Quantum Dots. Physical Review X, 8(2). https://doi.org/10.1103/PhysRevX.8.021058