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arXiv · 0707.1514

Effect of Two Level System Saturation on Charge Noise in Josephson Junction Qubits

Clare C. Yu·Magdalena Constantin·John M. Martinis
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Abstract

We show that charge noise $S_Q$ in Josephson qubits can be produced by fluctuating two level systems (TLS) with electric dipole moments in the substrate using a flat density of states. At high frequencies the frequency and temperature dependence of the charge noise depends on the ratio $J/J_c$ of the electromagnetic flux $J$ to the critical flux $J_c$. It is not widely appreciated that TLS in small qubits can easily be strongly saturated with $J/J_c\gg 1$. Our results are consistent with experimental conclusions that $S_Q\sim 1/f$ at low frequencies and $S_Q\sim f$ at high frequencies.

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Clare C. Yu, Magdalena Constantin, John M. Martinis. 2007-07-10. Effect of Two Level System Saturation on Charge Noise in Josephson Junction Qubits. https://arxiv.org/abs/0707.1514

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