Description From The Literature
A. Lupascu et al. give this description:
In quantum mechanics, the process of measurement is a subtle interplay between extraction of information and disturbance of the state of the quantum system. A quantum non-demolition (QND) measurement minimizes this disturbance by using a particular system—detector interaction that preserves the eigenstates of a suitable operator of the quantum system. This leads to an ideal projective measurement.
On the other hand, it has been argued that the usage of the term QND does not add anything to the usual notion of a strong quantum measurement and can moreover be confusing because of the two different interpretations of demolition in a quantum system (losing the quantum state vs. losing the particle). :
Read more about this topic: Quantum Nondemolition Measurement
Famous quotes containing the words description from, description and/or literature:
“I fancy it must be the quantity of animal food eaten by the English which renders their character insusceptible of civilisation. I suspect it is in their kitchens and not in their churches that their reformation must be worked, and that Missionaries of that description from [France] would avail more than those who should endeavor to tame them by precepts of religion or philosophy.”
—Thomas Jefferson (1743–1826)
“Do not require a description of the countries towards which you sail. The description does not describe them to you, and to- morrow you arrive there, and know them by inhabiting them.”
—Ralph Waldo Emerson (1803–1882)
“All men are lonely. But sometimes it seems to me that we Americans are the loneliest of all. Our hunger for foreign places and new ways has been with us almost like a national disease. Our literature is stamped with a quality of longing and unrest, and our writers have been great wanderers.”
—Carson McCullers (1917–1967)