A qubit device according to one aspect comprises: a semiconductor substrate; an elongate confinement arrangement; a first dielectric placed between the semiconductor substrate and the confinement arrangement to electrically separate the longitudinal confinement arrangement from the semiconductor substrate; a second dielectric longitudinally at least partially electrically insulating the confinement arrangement; a set of control gates arranged longitudinally along the confinement arrangement and separated from the confinement arrangement by the second dielectric. The control gates are configured to define one or more quantum dots in the confinement arrangement. A respective quantum dot is suitable for holding a spin qubit. The control gates comprise a set of first types of control gates and a set of second types of control gates arranged alternatingly along the confinement arrangement. The first types of control gates are ferromagnetic gates.