Abstract:
We study a two-mode cavity QED system, for an atom with Zeeman structure in its ground and excited states interacts with two orthogonal linear polarization modes of an optical cavity, via F = 3 to F0 = 4 transition. We take into account the full atomic level structure for this transition, including the Zeeman energy shift, as well as the atom's coupling to the two orthogonal modes of the cavity. We consider two different cases: one of the cavity modes is a) resonantly driven by a coherent field and b) driven by incoherent light; while light in the other cavity mode, in both cases, is generated only through spontaneous emission. For the coherent field case, we adopt a semiclassical treatment for the driven cavity mode and adiabatically eliminate the non-driven mode. A semiclassical treatment is not suitable for incoherent light, thus we adiabatically eliminate the driven and non-driven mode. Assuming that the atoms act as independent emitters, we are able to compute second-order correlation function for the non-driven mode from an atomic ensemble. We find that the system presents quantum beats and are visible only in the intensity autocorrelation function. The case for coherent driving exhibits two sources of oscillation, corresponding single atom beating of two ground states and two photons of different atoms. The incoherent case has only one source of beating corresponding to single atom beating of two ground states. The system shows a transition from antibunching to bunching as we increase the number of atoms in the cavity.
