Nondistortion quantum interrogation using Einstein-Podolsky-Rosen entangled photons
Xingxiang Zhou, Zheng-Wei Zhou, M. J. Feldman, Guang‐Can Guo · Physical Review A · 2001
We propose a scheme for nondistortion quantum interrogation defined as an interaction-free measurement that preserves the internal state of the object being detected. In our scheme, two Einstein-Podolsky-Rosen entangled photons are used as the probe and polarization-sensitive measurements are performed at the four ports of the Mach-Zehnder interferometer. In comparison with the previous single-photon scheme, it is shown that the two-photon approach has a higher probability of initial state preserving interrogation of an atom prepared in a quantum superposition. In the case that the presence of the atom is not successfully detected, the experiment can be repeated since the initial state of the atom is unperturbed.