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Flux qubit as a sensor for a magnetometer with quantum limited sensitivity

E. Il'ichev·Ya. S. Greenberg
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Abstract

We propose to use the quantum properties of a superconducting flux qubit in the construction of a magnetometer with quantum limited sensitivity. The main advantage of a flux qubit is that its noise is rather low, and its transfer functions relative to the measured flux can be made to be about 10mV/$Φ_0$, which is an order of magnitude more than the best value for a conventional SQUID magnetometer. We analyze here the voltage-to-flux, the phase-to-flux transfer functions and the main noise sources. We show that the experimental characteristics of a flux qubit, obtained in recent experiments, allow the use of a flux qubit as magnetometer with energy resolution close to the Planck constant.

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E. Il'ichev, Ya. S. Greenberg. 2006-08-18. Flux qubit as a sensor for a magnetometer with quantum limited sensitivity. https://doi.org/10.1209/0295-5075%2F77%2F58005

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