The Decoherence Sources of a Superconducting Quantum Bit
G. Ithiera , E. Collina , P.J. Meesonb , P. Joyeza, D. Viona , D. Estevea , F. Chiarelloc, A. Shnirmand , Y.
Makhlind , and G. Schönd
a
CEA-Saclay, Orme des Merisiers, 91191 Gif sur Yvette Cedex, France
Department of Physics, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
c
Istituto di Fotonica e Nanotecnologia, CNR, Via Cineto Romano, 42 00156 Roma, Italy
d
Institut für Theoretische Festkörperphysik, Universität Karlsruhe, D-76128 Karlsruhe, Germany
b
The Quantronium1 , a superconducting circuit with Josephson junctions, can be regarded as a solid state
qubit prototype with a coupling to the environment over which some degree of control may be exercised.
We have demonstrated experimentally that the quantum state of the circuit may be manipulated using
pulse sequences derived from NMR and atomic physics and then readout2 . Measurements of the coherence
time obtained in this way are analysed via a general theoretical framework to develop a simple model of
the environmental noise sources. A complete picture of decoherence in this quantum electrical circuit is
thus provided.
1
2
D. Vion et al., Science, 296, 886, (2002).
E. Collin et al., Phys. Rev. Lett. 93, 15, (2004).
Sorting category: Bc Superconductivity
Keywords: superconductivity, qubit, decoherence
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