The superposition principle is at the heart of the most intriguing features of the microscopic
world. A quantum system may exist in a linear superposition of different eigenstates of an
observable. It is then, in some way,''suspended''between different classical realities: a ...

We have observed the Rabi oscillation of circular Rydberg atoms in the vacuum and in small
coherent fields stored in a high Q cavity. The signal exhibits discrete Fourier components at
frequencies proportional to the square root of successive integers. This provides direct ...

Pairs of atoms have been prepared in an entangled state of the Einstein-Podolsky-Rosen
(EPR) type. They were produced by the exchange of a single photon between the atoms in a
high Q cavity. The atoms, entangled in a superposition involving two different circular ...

FIG. 2. Detection time sequence. a, Ionization field; b, detection of the 23$ initial level; c,
detection of the 22P final level. state analyzed by ionization with an electric field applied
between two 4-mm-distant paral. lel condenser plates (Fig. 1, line b). The resulting elec- ...

Abstract After quantum particles have interacted, they generally remain in an entangled state
and are correlated at a distance by quantum-mechanical links that can be used to transmit
and process information in nonclassical ways. This implies programmable sequences of ...

The detection of light intensity by usual photocounting techniques is field destructive.
Successive measurements of the intensity yield different results, as the initial field is
depleted by the continuing measuring process. Methods to avoid the" back action" of the ...

Following a recent proposal by SB Zheng and GC Guo [Phys. Rev. Lett. 85, 2392 (2000)], we
report an experiment in which two Rydberg atoms crossing a nonresonant cavity are
entangled by coherent energy exchange. The process, mediated by the virtual emission ...