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Decoherence of a Superconducting Qubit due to Bias Noise



John M. Martinis, Sae Woo Nam, Joe Aumentado, Kristine Lang, C Urbina


We calculate for the current-biased Josephson junction the decoherence of the qubit state from noise and dissipation. The effect of dissipation can be entirely accounted for through a noise model of the current bias that appropriately includes the effect of zero-point and thermal fluctuations from dissipation. The magnitude and frequency-dependence of this dissipation can be fully evaluated with this model to obtain design constraints for small decoherence. We also calculate decoherence from spin echo and Rabi control sequences and show they are much less sensitive to low-frequency noise. We predict small decoherence rates from 1/f noise of charge, critical current, and flux based on noise measurements in prior experiments. Our results indicate this system is a good candidate for a solid-state quantum computer.
Physical Review B (Condensed Matter and Materials Physics)


1/f noise, coherence, quantum computer, qubit, superconductivity


Martinis, J. , Nam, S. , Aumentado, J. , Lang, K. and Urbina, C. (2003), Decoherence of a Superconducting Qubit due to Bias Noise, Physical Review B (Condensed Matter and Materials Physics) (Accessed April 12, 2024)
Created March 24, 2003, Updated October 12, 2021