Abstract
We discuss the characterization and properties of quantum nondemolition (QND) measurements on qubit systems. We introduce figures of merit which can be applied to systems of any Hilbert space dimension, thus providing universal criteria for characterizing QND measurements. The controlled-NOT gate and an optical implementation are examined as examples of QND devices for qubits. We also consider the QND measurement of weak values.
- Received 20 December 2004
- Corrected 8 February 2006
DOI:https://doi.org/10.1103/PhysRevA.73.012113
©2006 American Physical Society
Corrections
8 February 2006