Controlling Surface Oxidation of Superconducting Circuit Materials

Achieving large-scale quantum computations with superconducting quantum circuits, particularly those based on transmon qubits, demands significant improvements in qubit coherence time. In recent advancements, tantalum (Ta) has emerged as a leading candidate, outperforming traditional counterparts in terms of coherence time. Despite its promise, the presence of an amorphous surface Ta oxide layer poses a challenge, potentially introducing dielectric loss and limiting the coherence time. In this talk, we will present a novel approach for suppressing the formation of surface Ta oxide, aiming to unlock the full potential of Ta-based quantum circuits for high-performance quantum computing applications.