Low-frequency measurement of the tunneling amplitude in a flux qubit

Abstract

We have observed signatures of resonant tunneling in an Al three-junction qubit, inductively coupled to a Nb LC tank circuit. The resonant properties of the tank oscillator are sensitive to the effective susceptibility (or inductance) of the qubit, which changes drastically as its flux states pass through degeneracy. The tunneling amplitude is estimated from the data. We find good agreement with the theoretical predictions in the regime of their validity.

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Cited by in corpus (9)

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• Observation of macroscopic Landau-Zener transitions in a superconducting device
• Direct Josephson coupling between superconducting flux qubits
• Mediated tunable coupling of flux qubits
• Possible implementation of adiabatic quantum algorithm with superconducting flux qubits
• Quantum tunneling of semifluxons
• Low frequency Rabi spectroscopy for a dissipative two-level system
• Hamiltonian for coupled flux qubits