Search

Superconducting niobium (Nb) thin films have recently attracted significant attention due to their utility for quantum information technologies. In the processing of Nb thin films, fluoride‐based chemical etchants are commonly used to remove surface oxides that are known to affect superconducting quantum devices adversely. However, these same etchants can also introduce hydrogen to form Nb hydrides, potentially negatively impacting microwave loss performance. Here, comprehensive materials characterization of Nb hydrides formed in Nb thin films as a function of fluoride chemical treatments is presented. In particular, secondary‐ion mass spectrometry, X‐ray scattering, and transmission electron microscopy reveal the spatial distribution and phase transformation of Nb hydrides. The rate of hydride formation is determined by the fluoride solution acidity and the etch rate of Nb2O5, which acts as a diffusion barrier for hydrogen into Nb. The resulting Nb hydrides are detrimental to Nb superconducting properties and lead to increased power‐independent microwave loss in coplanar waveguide resonators. However, Nb hydrides do not correlate with two‐level system loss or device aging mechanisms. Overall, this work provides insight into the formation of Nb hydrides and their role in microwave loss, thus guiding ongoing efforts to maximize coherence time in superconducting quantum devices. [ABSTRACT FROM AUTHOR]

This article is an editorial that discusses the role of disorder in superconductors and its impact on their properties. The authors highlight the importance of studying defects and imperfections in superconductors for both fundamental and applied research. They explore how disorder can both decrease and enhance the performance of superconductors, and how it can be used as a probe to study the fundamental aspects of superconductivity. The article also provides a summary of several review articles and original research papers that delve into different aspects of disorder and superconductivity. [Extracted from the article]

Disorder, confinement, and symmetry breaking contribute to the formation of new phases when liquid helium-3 is infused in a highly porous random solid such as a silica aerogel. [ABSTRACT FROM AUTHOR]