Title: Shuttling Domain Wall Qubit on the Magnetic Racetrack
Abstract: We propose a scalable implementation of a quantum computer based on hardware-efficient mobile domain walls on magnetic racetracks. In our proposal, quantum information is encoded in the chirality of the spin structure of nanoscale domain walls. We estimate that these qubits have long lifetimes and can be operated at sweet spots, reducing potential noise sources. Single-qubit gates are implemented by controlling the movement of walls in magnetic nanowires, while two-qubit entangling gates leverage naturally emerging interactions between different walls. These gates enable universal quantum computing and are fully compatible with current state-of-the-art experiments on racetrack memories. We also discuss possible schemes for qubit readout and initialization.