Two-Level Atoms and Cavity QED

Faisal Mehmood, Muhammad Waseem, Muhammad Irfan +1 more

Ullrich Martini, Axel Schenzle

Moonjoo Lee, Wontaek Seo, Hyun-Gue Hong +2 more

We report the measurement of the population and coherence of identically prepared two-level atoms with the cavity-QED microlaser. The atomic superposition state after coherent interaction with a pump field is directly mapped to the intra-cavity photon number and frequency shift of the microlaser. Our scheme is applicable to quantum information as a tool for analyzing a two-level atomic qubit.

Harry J. Kimble, J. McKeever

J Leach, C Elliot Strimbu, Perry R. Rice

We investigate intensity cross-correlation functions for two cavity QED systems. These are a driven optical cavity containing a single two-level atom interacting with a single mode of the cavity field with quantized centre of mass motion, and a two-level atom in an optical parametric oscillator. We find analytic results in the weak driving field limit using quantum trajectory theory. We find large violations of inequalities that must be satisfied by classical fields. One of these inequalities is well known, g (2) ij (τ) ≤ √g (2) jj (0)g (2) jj (0), where i and j denote two modes of the field. We also derive a new inequality that cross-correlations must satisfy, |g (2) ij (τ) - 1| 2 ≤ |(g (2) ii (0) - 1)(g (2) jj (0) - 1)|. Large violations of classical inequalities and asymmetrical behaviour in delay time τ are found in complimentary regimes for the cavity QED system with quantized centre of mass motion. They always exist for the two-level atom inside an optical parametric oscillator.

Zhong Zhi-Rong, Sai-Yun Ye, Wan-Jun Su

A scheme for approximately conditional teleportation of an arbitrary two-particle state without Bell-state measurement in cavity QED is presented. The scheme involves four two-level atoms and two single-mode cavities. The detection of atoms 3 and 4 collapses the atoms 1 and 2 to the initial state of atoms 3 and 4, while the cavity fields left in the vacuum state. The probability of success and the fidelity of our scheme are 0.125 and 0.98, respectively.