Decoherence-free spin entanglement generation and purification in nanowire double quantum dots

Abstract

We propose a deterministic generation and purification of decoherence-free spin entangled states with singlet-triplet spins in nanowire double quantum dots via resonator-assisted charge manipulation and measurement techniques. Each spin qubit corresponds to two electrons in a double quantum dot in the nanowire, with the singlet and one of the triplets as the decoherence-free qubit states. The logical qubits are immunized against the dominant source of decoherence-dephasing—while the influences of additional errors are shown by numerical simulations. We analyse the performance and stability of all required operations and emphasize that all techniques are feasible in current experimental conditions.