Systematic studies of surface smoothness of quantum solid thin films

There has been considerable recent interest in using electrons trapped on the surface of quantum solids as a platform for quantum information processing. A primary advantage of this platform is the quasi-vacuum environment that these surface electrons occupy, free from the deleterious influence of two-level fluctuators, quasiparticles, and dangling bonds due to the high purity of quantum solids. To enable improved qubit performance, reduced charge noise, and potential scalability, methods need to be developed to reliably and controllably grow ultrasmooth quantum solid thin films.



In this talk, I will present our studies of surface smoothness on two quantum solids, solid neon and solid hydrogen, which are of specific interest for use in quantum information processing. Using low-frequency AC mobility measurements to characterize surface smoothness, we compare the outcomes of films grown on silicon and sapphire via quench condensation or triple-point wetting. Additionally, we explore the effects of annealing in improving the surface smoothness.