Publications by authors named "Cameron Kopas"
Improving the qubit's lifetime (T) is crucial for fault-tolerant quantum computing. Recent advancements have shown that replacing niobium (Nb) with tantalum (Ta) as the base metal significantly increases T, likely due to a less lossy native surface oxide. However, understanding the formation mechanism and nature of both surface oxides is still limited.
View Article and Find Full Text PDFSuperconducting thin films of niobium have been extensively employed in transmon qubit architectures. Although these architectures have demonstrated improvements in recent years, further improvements in performance through materials engineering will aid in large-scale deployment. Here, we use information retrieved from secondary ion mass spectrometry and electron microscopy to conduct a detailed assessment of the surface oxide that forms in ambient conditions for transmon test qubit devices patterned from a niobium film.
View Article and Find Full Text PDFArticle Synopsis
- The text discusses a specific class of 2D quantum materials known as RTe (where R is a lanthanide) that exhibit unique quantum properties like superconductivity and charge density waves (CDW).
- It highlights the significance of RTe materials for studying CDW formation driven by Fermi surface nesting, noting the presence of multiple energy gaps indicative of complex CDW ordering.
- The review covers the fundamentals of these materials, recent advancements in their electronic and magnetic properties, and various synthesis methods, alongside potential applications.
Article Synopsis
- A high-pressure soft sputtering technique enables the growth of large-area 1T' phase MoTe sheets on HOPG and AlO substrates at relatively low temperatures (300 °C).
- The study found that a single co-sputtering step resulted in highly defected films, but using a two-step technique—first depositing on an unheated substrate followed by annealing—significantly improved the stoichiometry of the films.
- The best MoTe film synthesized had a low tellurium vacancy content and demonstrated n-type conductivity, highlighting the potential for large-scale production of tellurium-based materials while also addressing the difficulties in achieving stoichiometric MoTe thin films.