Interaction of a two level atom with many photons

V. Ernst

Rakesh Kumar Rai, Hari Prakash

We study sub-Poissonian photon statistics of light in interaction of a single mode radiation, initially either in a coherent state or in a superposed coherent state with an assembly of two-level atoms using the Hamiltonian, H = ω(a+a + Sz) + g(aS+ + a+ S–) in natural units, where a+ and a are creation and annihilation operators, Sz, S ± are the collective Dicke operators, g is the coupling constant, and ω is the energy of the photons and also the separation between the two atomic levels. We study the cases of (i) a single two-level and (ii) of two two-level atoms interacting with a single mode coherent or superposed coherent radiation. We find that for large coupling time gt, Fano factor shows collapses and revival phenomena, and that the variation is large for small mean number of photons. We also find that in the case of two two-level atoms, photon statistics shows larger sub-Poissonian than the case of a single two-level atom, and that there is no definite relationship between squeezing and sub-Poissonian photon statistics of light.

Aranya B. Bhattacherjee

It is shown that nonlinear interaction between two-level atom and the radiation field can profoundly modify the optical force experienced by the atom The dynamic stark shift now provides a cooling force even at zero detuning.Due to two-photon interaction the 'radiation pressure force' experienced by the atom is twice as large as that for one-photon case, consequently temperatures much lower than the one-photon limit can be achieved Keywords Two-photon interaction, laser cooling, optical force

P. van der Straten, Harold J. Metcalf

Shaozheng Jin

Multiphoton interaction of single-mode squeezed-state light and a two-level atom is considered based on the K-photon Jaynes–Cummings model. Time evolution of quantum fluctuation and photon statistical properties of the initial squeezing light are discussed. It is found that through interaction with a two-level atom, larger squeezing levels cannot be achieved in one-photon or multiphoton processes. For photon antibunching behavior of the light field, it is shown that a smaller initial squeezing level and an appropriately larger coherent part of the initial average photon number of the radiation field favor the generation of this nonclassical behavior, especially in the lower-order interaction processes.