Characterization of low-temperature microwave loss of thin aluminum oxide formed by plasma oxidation

Abstract

We report on the characterization of microwave loss of thin aluminum oxide films at low temperatures using superconducting lumped resonators. The oxide films are fabricated using plasma oxidation of aluminum and have a thickness of 5 nm. We measure the dielectric loss versus microwave power for resonators with frequencies in the GHz range at temperatures from 54 to 303 mK. The power and temperature dependence of the loss is consistent with the tunneling two-level system theory. These results are relevant to understanding decoherence in superconducting quantum devices. The obtained oxide films are thin and robust, making them suitable for capacitors in compact microwave resonators.

References in corpus (5)

• Experimental evidence for a surface distribution of two-level systems in superconducting lithographed microwave resonators
• Contribution of dielectrics to frequency and noise of NbTiN superconducting resonators
• Improving the Quality Factor of Microwave Compact Resonators by Optimizing their Geometrical Parameters
• Single crystal silicon capacitors with low microwave loss in the single photon regime
• Anomalous avoided level crossings in a Cooper-pair box spectrum

Cited by in corpus (11)

• Towards understanding two-level-systems in amorphous solids -- Insights from quantum circuits
• Materials loss measurements using superconducting microwave resonators
• Electric field spectroscopy of material defects in transmon qubits
• Characterization and reduction of microfabrication-induced decoherence in superconducting quantum circuits
• Merged-Element Transmons: Design and Qubit Performance
• Quantum Sensors for Microscopic Tunneling Systems
• Dielectric loss extraction for superconducting microwave resonators
• Fabrication and characterization of aluminum SQUID transmission lines
• Compact superconducting microwave resonators based on Al-AlOx-Al capacitor
• Quantum defects from single surface exhibit strong mutual interactions
• Non-demolition fluorescence readout and high-fidelity unconditional reset of a fluxonium qubit via dissipation engineering