JOSEPHSON CHARGE-PHASE QUBIT WITH THE RADIO FREQUENCY READOUT: COUPLING AND DECOHERENCE
Zorin A.B.

Received: December 10, 2003

PACS: 74.50.+r, 85.25.Cp, 03.67.Lx

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The Josephson qubit based on a superconducting single charge transistor inserted in a low-inductance superconducting loop is considered. The loop is inductively coupled to a radio-frequency driven tank circuit enabling the readout of the qubit states by measuring the effective Josephson inductance of the transistor. The effect of qubit dephasing and relaxation due to electric and magnetic control lines as well as the measuring system is evaluated. Recommendations for the qubit operation with minimum decoherence are given.