Real-time Monitoring of Neon Film Growth for Electron-on-Neon Qubits

Single electrons floating on the surface of neon and manipulated using circuit quantum electrodynamics (circuit QED) is a promising platform for quantum computing. Controlled neon growth is a necessity for the development of this platform into a viable quantum technology. To this end, we demonstrate a real-time neon film-growth monitor using high-T_c YBCO microwave resonators. We study liquid and solid films with thicknesses ranging from 100 nm to 10 μm. For solid films grown from the liquid phase and cooled across the triple point, the final film thickness varies stochastically from below 10 nm to above 1 μm. We characterize the effect of cooling rate, microwave probing power, and neon volume on the wetting and thinning dynamics in the vicinity of neon’s triple point. Our approach is a step towards fine control of neon growth for electron-on-neon (eNe) qubits.