Two-photon nonlinearity in general cavity QED systems (6 pages)

Kazuki Koshino, Hajime Ishihara

L. Ye, Guang‐Can Guo, Long-Bao Yu

Kazuki Koshino, Hajime Ishihara

We have investigated two-photon nonlinearity in general cavity QED systems, which cover both weak- and strong-coupling regimes and include the radiative loss from an atom. One- and two-photon propagators are obtained in analytical forms. By surveying both coupling regimes, we have revealed the conditions on a photonic pulse for yielding large nonlinear effects, depending on the cavity $Q$ value. We also discuss the effects of radiative loss on nonlinearity.

S. K. Bose, Moorad Alexanian

Akira Ishikawa, Hajime Ishihara

We propose a new scheme for strong two-photon nonlinearity (TPN) by cavity QED systems with many three-level atoms, although the TPN due to the saturation effect of two-level atoms generally declines with an increase in the number of atoms. The reduction in anharmonicity by the increase in the number of atoms can be overcome if the system satisfies particular criteria. The new scheme is significant for realizing TPN devices using solid-state materials because it is generally difficult to control the number of atoms, which are few, introduced in the device.

Kazuki Koshino

The nonlinear dynamics of a classical photon pulse occurring at a two-sided cavity QED system in the weak-coupling regime is investigated theoretically. It is shown that this system functions as a single-photon filter.