Quantum-mechanical effects at the macroscopic level were first explored in Josephson-
junction-based superconducting circuits in the 1980s. In recent decades, the emergence of …

Amorphous solids show surprisingly universal behaviour at low temperatures. The
prevailing wisdom is that this can be explained by the existence of two-state defects within …

The aim of this review is to provide quantum engineers with an introductory guide to the
central concepts and challenges in the rapidly accelerating field of superconducting …

The unique features of quantum theory offer a powerful new paradigm for information
processing. Translating these mathematical abstractions into useful algorithms and …

The performance of superconducting circuits for quantum computing is limited by materials
losses. In particular, coherence times are typically bounded by two-level system (TLS) …

We demonstrate a planar, tunable superconducting qubit with energy relaxation times up to
44 μ s. This is achieved by using a geometry designed to both minimize radiative loss and …

Superconducting qubits are a leading system for realizing large-scale quantum processors,
but overall gate fidelities suffer from coherence times limited by microwave dielectric loss …

Significant advances in coherence render superconducting quantum circuits a viable
platform for fault-tolerant quantum computing. To further extend capabilities, highly coherent …

Interest in superconducting microresonators has grown dramatically over the past decade.
Resonator performance has improved substantially through the use of improved geometries …

We study the energy relaxation times (T 1) of superconducting transmon qubits in 3D
cavities as a function of dielectric participation ratios of material surfaces. This surface …