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arXiv · 0709.2459

Quantum theory of the low-frequency linear susceptibility of interferometer-type superconducting qubits

Ya. S. Greenberg·E. Il'ichev
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Abstract

We use the density matrix formalism to analyze the interaction of interferometer-type superconducting qubits with a high quality tank circuit, which frequency is well below the gap frequency of a qubit. We start with the ground state characterization of the superconducting flux and charge qubits. Then, by making use of a dressed state approach we describe the qubits' spectroscopy when the qubit is irradiated by a microwave field which is tuned to the gap frequency. The last section of the paper is devoted to continuous monitoring of qubit states by using a DC SQUID in the inductive mode.

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Ya. S. Greenberg, E. Il'ichev. 2008-04-02. Quantum theory of the low-frequency linear susceptibility of interferometer-type superconducting qubits. https://doi.org/10.1103/physrevb.77.094513

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