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:
“Where there is the necessary technical skill to move mountains, there is no need for the faith that moves mountains.”
—Eric Hoffer (1902–1983)
“... we all know the wag’s definition of a philanthropist: a man whose charity increases directly as the square of the distance.”
—George Eliot [Mary Ann (or Marian)