Phys. Rev. B 64, 165310 (2001) [5 pages]Continuous weak measurement of quantum coherent oscillationsReceived 22 February 2001; revised 8 May 2001; published 5 October 2001 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. © 2001 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevB.64.165310
DOI:
10.1103/PhysRevB.64.165310
PACS:
73.23.-b, 03.65.Ta
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.