6 papers
Quantum solitons and their quantum walks in transmon arrays
Ben Blain, Giampiero Marchegiani, Luigi Amico +1
Superconducting qubits are artificial atoms whose spectra and interactions can be engineered through appropriate circuit design, a versatility that can be exploited for quantum sim…
Fraxonium: Fractional fluxon states for qudit encoding
Luca Chirolli, Valentina Brosco, Uri Vool +2
We propose a superconducting circuit hosting low-lying states, well separated from the rest of the spectrum, that naturally realizes a qudit system protected from leakage error…
Proximity effect in asymmetric-gap superconducting bilayers and regularization of transition rates
G. Marchegiani, G. Catelani
The standard mean-field treatment of low-temperature superconductors leads to a square-root divergent density of states at the gap value. This feature can lead to unphysical logari…
Magnetic-Field and Temperature Limits of a Kinetic-Inductance Traveling-Wave Parametric Amplifier
Lucas M. Janssen, Farzad Faramarzi, Henry G. LeDuc +5
Kinetic-inductance traveling-wave parametric amplifiers (KI-TWPAs) offer broadband near-quantum-limited amplification with high saturation power. Due to the high critical magnetic…
Nonequilibrium regimes for quasiparticles in superconducting qubits with gap-asymmetric junctions
G. Marchegiani, G. Catelani
Superconducting qubits hold promise for quantum computing, but their operation is challenged by various sources of noise, including excitations known as quasiparticles. Qubits with…
Excess quasiparticles and their dynamics in the presence of subgap states
P. B. Fischer, G. Catelani
Material inhomogeneities in a superconductor generically lead to broadening of the density of states and to subgap states. The latter are associated with spatial fluctuations of th…