During the last ten years, superconducting circuits have passed from being interesting
physical devices to becoming contenders for near-future useful and scalable quantum …

Superconducting qubit lifetimes must be both long and stable to provide an adequate
foundation for quantum computing. This stability is imperiled by two-level systems (TLSs) …

Quantum-computation architecture based on d-level systems, or qudits, has attracted
considerable attention recently due to their enlarged Hilbert space. Extensive theoretical …

Nitrogen vacancy (NV) centers in diamond are atom-scale defects that can be used to sense
magnetic fields with high sensitivity and spatial resolution. Typically, the magnetic field is …

Identifying, quantifying, and suppressing decoherence mechanisms in qubits are important
steps towards the goal of engineering a quantum computer or simulator. Superconducting …

Using quantum systems with more than two levels, or qudits, can scale the computational
space of quantum processors more efficiently than using qubits, which may offer an easier …

We study experimentally and numerically the noisy evolution of multipartite entangled states,
focusing on superconducting qubit devices accessible via the cloud. We find that a valid …

Designing the spatial profile of the superconducting gap—gap engineering—has long been
recognized as an effective way of controlling quasiparticles in superconducting devices. In …

Recent research shows that quasiparticle-induced decoherence of superconducting qubits
depends on the superconducting-gap asymmetry originating from the different thicknesses …

Building usefully coherent superconducting quantum processors depends on reducing
losses in their constituent materials [I. Siddiqi, Nat. Rev. Mater. 6, 875–891 (2021)] …