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)
“God damnit, why must all those journalists be such sticklers for detail? Why, they’d hold you to an accurate description of the first time you ever made love, expecting you to remember the color of the room and the shape of the windows.”
—Lyndon Baines Johnson (1908–1973)
“One of the necessary qualifications of an efficient business man in these days of industrial literature seems to be the ability to write, in clear and idiomatic English, a 1,000-word story on how efficient he is and how he got that way.... It seems that the entire business world were devoting its working hours to the creation of a school of introspective literature.”
—Robert Benchley (1889–1945)