Continuous weak measurement of quantum coherent oscillations

2000/02/14 by Alexander N. Korotkov, A. N. Korotkov, D. V. Averin · 4 citations
Computer Science · Mathematics · Physics and Astronomy · #Coherent states #Dephasing #Detector #Limit (mathematics) #Mathematical analysis #Mathematics #Mechanical and Optical Resonators #Noise (video) #Optics #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum limit #Quantum measurement #Quantum mechanics #Quantum system #Weak measurement #cond-mat.mes-hall #quant-ph

paper · pdf · doi:10.1103/physrevb.64.165310

published as Phys. Rev. B 64, 165310 (2001)

arxiv created 2000/02/14 · openalex publication_date 2001/10/05 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We consider the problem of continuous quantum measurement of coherent oscillations between two quantum states of an individual two-state system. It is shown that the interplay between the information acquisition and the backaction dephasing of the oscillations by the detector imposes a fundamental limit, equal to four, on the signal-to-noise ratio of the measurement. The limit is universal, e.g., independent of the coupling strength between the detector and system, and results from the tendency of quantum measurement to localize the system in one of the measured eigenstates.

Citations

• Coherent control of macroscopic quantum states in a single-Cooper-pair box
• Dephasing and the Orthogonality Catastrophe in Tunneling through a Quantum Dot: the ``Which Path?'' Interferometer
• Dephasing in a quantum dot due to coupling with a quantum point contact

Cited by

• The Informational Observer in Relational Quantum Mechanics
• Measurement Back-Action in Stacked Graphene Quantum Dots
• Entangled quantum currents in distant mesoscopic Josephson junctions
• Tunneling without tunneling: wavefunction reduction in a mesoscopic qubit