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arXiv · 2402.10775

Intermodulation spectroscopy and the nonlinear response of two-level systems in superconducting coplanar waveguide resonators

Janka Biznárová·J. C. Rivera Hernández·Daniel Forchheimer·Jonas Bylander·David B. Haviland·Gustav Andersson
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Abstract

Two-level system (TLS) loss is typically limiting the coherence of superconducting quantum circuits. The loss induced by TLS defects is nonlinear, resulting in quality factors with a strong dependence on the circulating microwave power. We observe frequency mixing due to this nonlinearity by applying a two-tone drive to a coplanar waveguide resonator and measuring the intermodulation products using a multifrequency lock-in technique. This intermodulation spectroscopy method provides an efficient approach to characterizing TLS loss in superconducting circuits. Using harmonic balance reconstruction, we recover the nonlinear parameters of the device-TLS interaction, which are in good agreement with the standard tunnelling model for TLSs.

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Janka Biznárová, J. C. Rivera Hernández, Daniel Forchheimer, Jonas Bylander, David B. Haviland, Gustav Andersson. 2024-02-16. Intermodulation spectroscopy and the nonlinear response of two-level systems in superconducting coplanar waveguide resonators. https://doi.org/10.1103/physrevapplied.22.014063

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