Nonequilibrium quasiparticle distribution in superconducting resonators: effect of pair-breaking photons

Abstract

Many superconducting devices rely on the finite gap in the excitation spectrum of a superconductor: thanks to this gap, at temperatures much smaller than the critical one the number of excitations (quasiparticles) that can impact the device's behavior is exponentially small. Nevertheless, experiments at low temperature usually find a finite, non-negligible density of quasiparticles whose origin has been attributed to various non-equilibrium phenomena. Here, we investigate the role of photons with energy exceeding the pair-breaking threshold $2\Delta$ as a possible source for these quasiparticles in superconducting resonators. Modeling the interacting system of quasiparticles, phonons, sub-gap and pair-breaking photons using a kinetic equation approach, we find analytical expressions for the quasiparticles' density and their energy distribution. Applying our theory to measurements of quality factor as function of temperature and for various readout powers, we find they could be explained by assuming a small number of photons above the pair-breaking threshold. We also show that frequency shift data can give evidence of quasiparticle heating.

19 pages, 13 figures

References in corpus (31)

• Superconducting nanowire single-photon detectors: physics and applications
• Towards understanding two-level-systems in amorphous solids -- Insights from quantum circuits
• Relaxation and frequency shifts induced by quasiparticles in superconducting qubits
• Materials loss measurements using superconducting microwave resonators
• Measurement and Control of Quasiparticle Dynamics in a Superconducting Qubit
• Hot non-equilibrium quasiparticles in transmon qubits
• Quasiparticle dynamics in granular aluminum close to the superconductor to insulator transition
• Number fluctuations of sparse quasiparticles in a superconductor
• Superconducting nanowire for single-photon detection: progress, challenges and opportunities
• Vortex-induced dissipation in narrow current-biased thin-film superconducting strips
• Determining interface dielectric losses in superconducting coplanar waveguide resonators
• Photon Shot Noise Dephasing in the Strong-Dispersive Limit of Circuit QED
• Current Assisted, Thermally Activated Flux Liberation in Ultrathin Nanopatterned NbN Superconducting Meander Structures
• Non-Poissonian Quantum Jumps of a Fluxonium Qubit due to Quasiparticle Excitations
• Evidence of a nonequilibrium distribution of quasiparticles in the microwave response of a superconducting aluminium resonator
• Disentangling Losses in Tantalum Superconducting Circuits
• Interplay between kinetic inductance, non-linearity and quasiparticle dynamics in granular aluminum MKIDs
• Engineering superconducting qubits to reduce quasiparticles and charge noise
• Photon-assisted charge-parity jumps in a superconducting qubit
• Quasiparticle generation efficiency in superconducting thin-films
• Bogoliubov Quasiparticles in Superconducting Qubits
• Coherent excited states in superconductors due to a microwave field
• Quasiparticle number fluctuations in superconductors
• Non-equilibrium superconductivity in superconducting resonators
• Quasiparticles in superconducting qubits with asymmetric junctions
• Distinguishing parity-switching mechanisms in a superconducting qubit
• Non-equilibrium quasiparticles in superconducting circuits: photons vs. phonons
• Nonequilibrium superconducting thin films with sub-gap and pair-breaking photon illumination
• Quasiparticle dynamics in a superconducting qubit irradiated by a localized infrared source
• Nonequilibrium quasiparticle distribution in superconducting resonators: analytical approach
• Broadband illumination of superconducting pair breaking photon detectors

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