Physical Review A
Quantum-nondemolition determination of an atomic state via the optical Stern-Gerlach effect
S. M. Tan, Daniel F. Walls
Abstract
The near-resonant interaction of an atomic beam with an optical standing-wave field can produce a deflection of the beam that depends on the initial atomic state. We investigate the extent to which the momentum transfer may be regarded as a coherent nondestructive encoding of the internal atomic state on the center-of-mass motion. Techniques developed for analyzing quantum-nondemolition measurements are used to quantify the effectiveness of this encoding. The effects of varying the detuning and the profile of the optical beam are discussed using parameter values close to those recently realized experimentally by Sleator et al. [Phys. Rev. Lett. 68, 1996 (1992)].