Technical Definition
Consider a full Von Neumann measurement by giving a quantum description to both the system and the measuring apparatus . Suppose the dynamics can be described by a Hamiltonian of the form
where Hself is the self-interaction of the system and Hint is the coupling between the system and the measuring apparatus. Generally, the Hint term is modeled as "turning on" for only a brief time and yielding the ideal (weak) Von Neumann measurement:
This measurement is a QND measurement if
Read more about this topic: Quantum Nondemolition Measurement
Famous quotes containing the words technical and/or definition:
“The best work of artists in any age is the work of innocence liberated by technical knowledge. The laboratory experiments that led to the theory of pure color equipped the impressionists to paint nature as if it had only just been created.”
—Nancy Hale (b. 1908)
“... if, as women, we accept a philosophy of history that asserts that women are by definition assimilated into the male universal, that we can understand our past through a male lens—if we are unaware that women even have a history—we live our lives similarly unanchored, drifting in response to a veering wind of myth and bias.”
—Adrienne Rich (b. 1929)