Reading-out the state inductively and microwave spectroscopy of an interferometer-type charge qubit

Abstract

We implemented experimentally an interferometer-type charge qubit consisting of a single-Cooper-pair transistor closed by a superconducting loop that is in flip-chip configuration inductively coupled to a radio frequency tank circuit. The tank permits to readout the qubit state, acting as inductance measuring apparatus. By applying continuous microwave power to the quantum device, we observed inductance alterations caused by redistributions of the energy level populations. From the measured data, we extracted the energy gap between ground and upper levels as a function of the transistor quasicharge as well as the Josephson phase across both junctions.

4 pages, 5 figures, revised version, to appear in PRB Rapid Comm

Cited by in corpus (8)

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• Dressed-state amplification by a superconducting qubit
• Multiphoton transitions in Josephson-junction qubits (Review Article)
• Resonant excitations of single and two-qubit systems coupled to a tank circuit
• Enhanced coherence in superconducting circuits via band engineering
• Simulating long-distance entanglement in quantum spin chains by superconducting flux qubits
• Quantum theory of the low-frequency linear susceptibility of interferometer-type superconducting qubits
• Dynamical reentrance and geometry imposed quantization effects in Nb-AlOx-Nb Josephson junction arrays