1/f noise of Josephson-junction-embedded microwave resonators at single photon energies and millikelvin temperatures

Abstract

We present measurements of 1/f frequency noise in both linear and Josephson-junction-embedded superconducting aluminum resonators in the low power, low temperature regime - typical operating conditions for superconducting qubits. The addition of the Josephson junction does not result in additional frequency noise, thereby placing an upper limit for fractional critical current fluctuations of $10^{-8}$ (Hz${}^{-1/2}$) at 1 Hz for sub-micron, shadow evaporated junctions. These values imply a minimum dephasing time for a superconducting qubit due to critical current noise of 40 -- 1400 $\mu$s depending on qubit architecture. Occasionally, at temperatures above 50 mK, we observe the activation of individual fluctuators which increase the level of noise significantly and exhibit Lorentzian spectra.

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Cited by in corpus (9)

• Evidence for interacting two-level systems from the 1/f noise of a superconducting resonator
• Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits
• Measurement-induced qubit state mixing in circuit QED from up-converted dephasing noise
• Generalized Tunneling Model for TLS in amorphous materials and its predictions for their dephasing and the noise in superconducting microresonators
• Robust manipulation of superconducting qubits in the presence of fluctuations
• Low frequency resistance and critical current fluctuations in Al-based Josephson junctions
• Low temperature 1/f noise in microwave dielectric constant of amorphous dielectrics in Josephson qubits
• Exact decoherence dynamics of $1/f$ noise
• Hybrid cat-transmon architecture for scalable, hardware-efficient quantum error correction