Embodiments of a Majorana-based qubit are disclosed herein. The qubit is based on the formation of superconducting islands, some parts of which are topological (T) and some parts of which are non-topological. Also disclosed are example techniques for fabricating such qubits. In one embodiment, a semiconductor nanowire is grown, the semiconductor nanowire having a surface with an oxide layer. A dielectric insulator layer is deposited onto a portion of the oxide layer of the semiconductor nanowire, the portion being designed to operate as a non-topological segment in the quantum device. An etching process is performed on the oxide layer of the semiconductor nanowire that removes the oxide layer at the surface of the semiconductor nanowire but maintains the oxide layer in the portion having the deposited dielectric insulator layer. A superconductive layer is deposited on the surface of the semiconductor nanowire, including over the dielectric insulator layer.