Materials for Superconducting Quantum Devices

Superconducting circuits represent one of the most advanced quantum computing technologies, with quantum gate fidelities for superconducting qubits improving significantly over the past decade. Despite this remarkable progress, achieving even higher fidelities is crucial to enable practical quantum protocols and reduce the overhead required for fault-tolerant quantum computing. The primary sources of errors are control imperfections and decoherence. While control errors can be effectively mitigated through engineering advances, reducing decoherence is more complex, requiring insights at the intersection of physics and materials science. Currently, no definitive solution has been identified, and decoherence remains the most significant obstacle to achieving higher fidelities and realizing practical quantum information processing.

This special topic collection of articles is dedicated to covering recent advances in material research and fabrication for superconducting quantum devices. The topics of interest include but are not limited to interface engineering to reduce losses, such as the engineering of pristine interfaces, growth of low-loss oxides, and introduction of capping layers to prevent oxidation, two-level fluctuations in their role in dissipation and exploration of new superconductor materials and substrates in application to quantum devices. The special topic also welcomes new insights into the fabrication of highly coherent superconducting quantum devices and novel techniques to characterize losses and their mechanisms.

Guest Editors

Anna Grassellino, Fermilab

Alexander Romanenko, Fermilab

Peter Jacobson, University of Queensland

Arkady Federov, University of Queensland

About the Journal

Applied Physics Reviews (APR) features articles on important and current topics in experimental or theoretical research in applied physics or applications of physics to other branches of science and engineering. APR publishes the following types of articles:

• Original Research: An article reporting on an important and novel research study of high quality and general interest to the applied physics community.
• Reviews: This type of article can either be an authoritative, comprehensive review of established areas of applied physics, or a short timely review of recent advances in established fields or new and emerging areas of applied physics.