Flux Qubits with Long Coherence Times for Hybrid Quantum Circuits

M. Stern (1) , G. Catelani (2) , Y. Kubo (1) , C. Grezes (1) , A. Bienfait (1) , Denis Vion (1) , Daniel Esteve (1) , Patrice Bertet (1)

1 QUANTRONICS - Quantronics Group
2 Peter Grünberg Institut

We present measurements of superconducting flux qubits embedded in a three dimensional copper cavity. The qubits are fabricated on a sapphire substrate and are measured by coupling them inductively to an on-chip superconducting resonator located in the middle of the cavity. At their flux-insensitive point, all measured qubits reach an intrinsic energy relaxation time in the 6-20 microseconds range and a pure dephasing time comprised between 3 and 10 microseconds. This significant improvement over previous works opens the way to the coherent coupling of a flux-qubit to individual spins.

Keywords: PERSISTENT-CURRENT QUBIT; DECOHERENCE; STATE

Domains: Physics [physics]

M. Stern, G. Catelani, Y. Kubo, C. Grezes, A. Bienfait, et al.. Flux Qubits with Long Coherence Times for Hybrid Quantum Circuits. Physical Review Letters, 2014, 113 (12), pp.123601. ⟨10.1103/PhysRevLett.113.123601⟩. ⟨cea-01384637⟩