Quantum nondemolition-like fast measurement scheme for a superconducting qubit

I. Serban, Britton Plourde, F. K. Wilhelm

Research output: Contribution to journalArticle

13 Scopus citations


We present a measurement protocol for a flux qubit coupled to a dc-superconducting quantum interference device (SQUID), representative of any two-state system with a controllable coupling to a harmonic-oscillator quadrature, which consists of two steps. First, the qubit state is imprinted onto the SQUID via a very short and strong interaction. We show that at the end of this step the qubit dephases completely, although the perturbation of the measured qubit observable during this step is weak. In the second step, information about the qubit is extracted by measuring the SQUID. This step can have arbitrarily long duration, since it no longer induces qubit errors.

Original languageEnglish (US)
Article number054507
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number5
StatePublished - Aug 12 2008


ASJC Scopus subject areas

  • Condensed Matter Physics

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