Manipulating the Quantum State of an Electrical Circuit

Denis Vion (1) , A. Aassime (1) , A. Cottet (1) , P. Joyez (1) , H. Pothier (1) , C. Urbina (1) , Daniel Esteve (1) , M. Devoret (1)

1 QUANTRONICS - Quantronics Group

We have designed and operated a superconducting tunnel junction circuit that behaves as a two-level atom: the ``quantronium''. An arbitrary evolution of its quantum state can be programmed with a series of microwave pulses, and a projective measurement of the state can be performed by a pulsed readout sub-circuit. The measured quality factor of quantum coherence Qphi=25000 is sufficiently high that a solid-state quantum processor based on this type of circuit can be envisioned.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]; Supraconductivité [cond-mat.supr-con]; Physique Quantique [quant-ph]

Denis Vion, A. Aassime, A. Cottet, P. Joyez, H. Pothier, et al.. Manipulating the Quantum State of an Electrical Circuit. Science, 2002, 296, pp.886-889. ⟨hal-00021251⟩