2008/03/31 by I. Serban, B. L. T. Plourde, Frank K. Wilhelm +1
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum many-body systems #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.78.054507
published as Phys. Rev. B 78, 054507 (2008) · published version, minor corrections
openalex publication_date 2008/08/12 · arxiv created 2008/08/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
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.