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Mitigation of interfacial dielectric loss in aluminum-on-silicon superconducting qubits.
- Source :
- NPJ Quantum Information; 8/14/2024, Vol. 10 Issue 1, p1-8, 8p
- Publication Year :
- 2024
-
Abstract
- We demonstrate aluminum-on-silicon planar transmon qubits with time-averaged T<subscript>1</subscript> energy relaxation times of up to 270 μs, corresponding to Q = 5 million, and a highest observed value of 501 μs. Through materials analysis techniques and numerical simulations we investigate the dominant source of energy loss, and devise and demonstrate a strategy toward its mitigation. Growing aluminum films thicker than 300 nm reduces the presence of oxide, a known host of defects, near the substrate-metal interface, as confirmed by time-of-flight secondary ion mass spectrometry. A loss analysis of coplanar waveguide resonators shows that this results in a reduction of dielectric loss due to two-level system defects. The correlation between the enhanced performance of our devices and the film thickness is due to the aluminum growth in columnar structures of parallel grain boundaries: transmission electron microscopy shows larger grains in the thicker film, and consequently fewer grain boundaries containing oxide near the substrate-metal interface. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20566387
- Volume :
- 10
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- NPJ Quantum Information
- Publication Type :
- Academic Journal
- Accession number :
- 179042198
- Full Text :
- https://doi.org/10.1038/s41534-024-00868-z