Alternative Junction Oxides for Superconducting Qubits

Oxide characteristics, both at the metal surface and in the junction, are critical to superconducting qubit performance. Parasitic two-level systems residing in these oxides currently limit qubit coherence lifetimes. Junctions using Aluminium oxides grown via in situ evaporation and oxidation are ubiquitous in the state-of-the-art superconducting qubits. Motived by recent studies that link specific surface oxide materials with qubit lifetimes we explore alternative junction oxides and detail the development and characterization of new fabrication techniques for superconducting qubits.