Advancements in surface preparation of 3D niobium cavities for quantum memories

3D superconducting cavities are a promising platform for implementing long-lived quantum memories and for storing bosonic qubits with built-in error protection. Since the performance of the quantum memory strongly depends on the cavity's single photon lifetime, the improvement of the cavity's intrinsic quality factor is crucial. A primary cause of the degradation of the quality factor is the oxide layer that develops on the cavity's surface, resulting in photon loss induced by two-level systems in the oxide. We will present our efforts in tackling this oxide layer using various surface preparation methods. We show that these methods enable significant improvements in the cavity quality factor.