Spin Weyl quantum unit: A theoretical proposal

Superconducting qubits are important for practical implementation of quantum computers. Here, the authors propose a novel type of the superconducting qubit: the spin Weyl quantum unit, a four-state hybrid quantum system that combines states of a spin and an Andreev superconducting qubit. They demonstrate how the unit can be manipulated to achieve an arbitrary unitary transformation in the space of four states by controlling the superconducting phase only, and a convenient readout.