2004/06/22 by Andrew N. Jordan, Μ. Büttiker, Markus Buttiker · 3 citations
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum and electron transport phenomena #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevb.71.125333
published as Phys. Rev. B 71, 125333 (2005) · 7 pages, 1 figure
arxiv created 2004/06/22 · openalex publication_date 2005/03/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose a quantum nondemolition measurement using a kicked two-state system (qubit). By tuning the waiting time between kicks to be the qubit oscillation period, the kicking apparatus performs a nondemolition measurement. While dephasing is unavoidable, the nondemolition measurement can (1) slow relaxation of diagonal density matrix elements, (2) avoid detector back-action, and (3) allow for a large signal-to-noise ratio. Deviations from the ideal behavior are investigated by allowing for detuning of the waiting time, as well as finite-time, noisy pulses. The scheme is illustrated with a double-dot qubit measured by a gate-pulsed quantum point contact.