Two-level systems in superconducting quantum devices due to trapped quasiparticles

Abstract

A major issue for the implementation of large scale superconducting quantum circuits is the interaction with interfacial two-level system defects (TLS) that leads to qubit relaxation and impedes qubit operation in certain frequency ranges that also drift in time. Another major challenge comes from non-equilibrium quasiparticles (QPs) that result in qubit dephasing and relaxation. In this work we show that such QPs can also serve as a source of TLS. Using spectral and temporal mapping of TLS-induced fluctuations in frequency tunable resonators, we identify a subset of the general TLS population that are highly coherent TLS with a low reconfiguration temperature $\sim$ 300 mK, and a non-uniform density of states. These properties can be understood if these TLS are formed by QPs trapped in shallow subgap states formed by spatial fluctutations of the superconducting order parameter $\Delta$. Magnetic field measurements of one such TLS reveals a link to superconductivity. Our results imply that trapped QPs can induce qubit relaxation.

7 pages, 4 figures, plus 18 pages, 13 figures supplemental

References in corpus (49)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• 1/f noise: implications for solid-state quantum information
• The Flux Qubit Revisited to Enhance Coherence and Reproducibility
• Towards understanding two-level-systems in amorphous solids -- Insights from quantum circuits
• Fluctuations of Energy-Relaxation Times in Superconducting Qubits
• Decoherence benchmarking of superconducting qubits
• Measurement and Control of Quasiparticle Dynamics in a Superconducting Qubit
• Impact of ionizing radiation on superconducting qubit coherence
• Hot non-equilibrium quasiparticles in transmon qubits
• Correlating decoherence in transmon qubits: Low frequency noise by single fluctuators
• Single magnetic adsorbates on s-wave superconductors
• Thermal and Residual Excited-State Population in a 3D Transmon Qubit
• Observation of directly interacting coherent two-level systems in a solid
• Evidence for interacting two-level systems from the 1/f noise of a superconducting resonator
• Electric field spectroscopy of material defects in transmon qubits
• Reducing the impact of radioactivity on quantum circuits in a deep-underground facility
• Origin and Suppression of $1/f$ Magnetic Flux Noise
• Phase diagram of a strongly disordered s-wave superconductor, NbN, close to the metal-insulator transition
• Observation of classical-quantum crossover of 1/f flux noise and its paramagnetic temperature dependence
• Generalized Tunneling Model for TLS in amorphous materials and its predictions for their dephasing and the noise in superconducting microresonators
• High-speed phonon imaging using frequency-multiplexed kinetic inductance detectors
• Phonon traps reduce the quasiparticle density in superconducting circuits
• Suppression of 1/f noise in solid state quantum devices by surface spin desorption
• Universal scaling of the critical temperature for thin films near the superconducting-to-insulating transition
• Direct identification of dilute surface spins on Al${}_2$O${}_3$: Origin of flux noise in quantum circuits
• Universal scaling of the order-parameter distribution in strongly disordered superconductors
• Decoherence spectroscopy with individual two-level tunneling defects
• Analysis of high quality superconducting resonators: consequences for TLS properties in amorphous oxides
• Tail States in a Superconductor with Magnetic Impurities
• Position and energy-resolved particle detection using phonon-mediated microwave kinetic inductance detectors
• Mitigation of Cosmic Ray Effect on Microwave Kinetic Inductance Detector Arrays
• Tunneling dynamics between superconducting bound states at the atomic limit
• Tunneling study of cavity grade Nb: possible magnetic scattering at the surface
• Fast tunable high Q-factor superconducting microwave resonators
• Resolving the positions of defects in superconducting quantum bits
• Spectroscopic evidence for strong correlations between local superconducting gap and local Altshuler-Aronov density-of-states suppression in ultrathin NbN films
• Electron energy relaxation in disordered superconducting NbN films
• Microwave-induced excess quasiparticles in superconducting resonators measured through correlated conductivity fluctuations
• How many quasiparticles can be in a superconductor?
• Optimization of $Al/Al{O}_x/Al$-Layer Systems for Josephson Junctions from a Microstructure Point of View
• Surface impedance of superconductors with weak magnetic impurities
• Pound-locking for characterization of superconducting microresonators
• Superconductivity behavior in epitaxial TiN films points at surface magnetic disorder
• Subgap states in dirty superconductors and their effect on dephasing in Josephson qubits
• Handling Leakage with Subsystem Codes
• Transmon Qubit in a Magnetic Field: Evolution of Coherence and Transition Frequency
• Microscopic charging and in-gap states in superconducting granular aluminum
• Anomalous low-energy properties in amorphous solids and the interplay of electric and elastic interactions of tunneling two-level systems
• The role of the coherence length for the establishment of global phase coherence in three-dimensional arrays of ultra-thin quasi-one-dimensional superconducting Pb and NbN nanowires

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