Advancements in 3D cavity fabrication for improved quantum memories

High coherence 3D cavities have allowed for the creation of single and multimode quantum memories and the creation of non-trivial bosonic states that can be stabilized against decay. Scaling the number of accessible modes in these systems will require the creation of cavities with very long coherence times. In this talk we will discuss the creation of ~6.5GHz niobium coaxial cavities with single-photon internal quality factors in excess of 1.4 billion with conduction-limited quality factors greater than 3 billion. This will include a discussion of the surface processing and a characterization of the intrinsic loss mechanisms and methods for reducing these losses. Finally, we will discuss the challenges of qubit integration and the creation of single and multimodal quantum memories using such long-lived cavity states.