On the principle of quantum nondemolition measurements

V. P. Belavkin

Carlton M. Caves

Guoxi Fang, Yancheng Zhao

In this paper, the method will be introduced, it's called Quantum Nondemolition measurement. The purpose is to realize a new measuring method to surpass quantum limit. It provides a new method of overcoming quantum noise. In principle, it can use any precision to detect a certain weak signal. Finally, the application of QND Measurement in optical communication will be introduced.

Vladimir B. Braginsky, Farid Ya Khalili

The history of the theory of quantum nondemolition (QND) measurements from the 1920s until today is reviewed. The definition and main principles of QND measurements are outlined. Achievements in the experimental realization of QND measurements and several new promising schemes of QND measurements are described. A list of the most important problems (from the authors' point of view) in the area of QND measurements is presented. The problem of measurement of a quantum oscillator phase is considered. A new method of phase measurement is proposed. Examples of possible solutions of fundamental physical problems using QND methods are given.

F. Ia. Khalili

Daniel F. Walls, Gerard J Milburn