Spontaneous emission from two two-level entangled atoms

The properties of spontaneous emission from two identical two-level entangled atoms interacting with a multimode-vacuum field are reexamined from the view point of the degree of entanglement and the relative phase. We find that the total spontaneous emission rate depends on the degree of entanglement and the relative phase in general, and that in different cases, the positive correlation or the negative correlation exists in the two entangled atoms which leads to the well-known superradiation or subradiation. Moreover, in some cases, the superradiation or subradiation is very dependent on the degree of entanglement and the relative phase. In addition, the decoherence for the four Bell basis states, caused by interaction with the environment, is discussed. Finally, the properties of the spontaneous emission spectra for the triplet states are presented.