2006/06/30 by T. Gilad, S. A. Gurvitz · 1 citation
Computer Science · Physics and Astronomy · #Computer science #Density matrix #Detector #Interference (communication) #Materials science #Matrix (chemical analysis) #Noise (video) #Optics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum dot #Quantum mechanics #Quantum tunnelling #Qubit #SIGNAL (programming language) #Telecommunications #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevlett.97.116806
published as Phys. Rev. Lett., 97, 116806 (2006). · 4 pages, some explanations added, Phys. Rev. Lett., in press
arxiv created 2006/08/14 · openalex publication_date 2006/09/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We propose to monitor a qubit with a double-dot (DD) resonant-tunneling detector, which can operate at higher temperatures than a single-dot detector. In order to assess the effectiveness of this device, we derive rate equations for the density matrix of the entire system. We show that the signal-to-noise ratio can be greatly improved by a proper choice of the parameters and location of the detector. We demonstrate that quantum interference effects within the DD detector play an important role in the measurement. Surprisingly, these effects produce a systematic measurement error, even when the entire system is in a stationary state.