The study of the interaction between electromagnetic waves and matter in cavity atomicsystems is at the heart of many developments such as atom-field entanglement and thedevelopment of atomic memories . These phenomena have been observed in the situationof strong coupling between the photons and atoms in the cavity . Such a system offersfascinating nonclassical features of light: saueezing and antibunching.
The first occurs whensome noise component in the field is below the standard quantum limit and the secondcorresponds to a light with photons more equally spaced than a coherent field. Theseconcepts have been revisited in the field of condensed matter thanks to the development ofnew growth technologies for semiconductor heterostructures.In semiconductor structures, fundamental excitation is composed of an electron and a hole bound by Coulomb interaction, forming an exciton.
This particle can be created by the absorption of one or more photonsand may become excited radiatively. This exciton interacts with photons which themselvescan be confined in a cavity. By confining excitons and photons in one system, it is possibleto increase their mutual interactions and observe the regime of strong coupling, where theinteraction gives rise to a quasi-particle called polariton. The polariton is composed of aphotonic part, the photon of the cavity, and an excitonic part; it is therefore both light andmatter. Semiconductor microcavities in strong coupling regime have been since the subjectof intense research