Recently, Ye and Guo [Phys. Rev. A 70, 054303 (2004)] have presented a scheme for implementing quantum teleportation of atomic states in cavity QED. In this Comment, we show that contrary to the authors' claim, the scheme is based on Bell-state measurement.
In a previous work [Commun. Theor. Phys. 45 (2006) 79] a scheme was presented for approximate and conditional teleportation of an unknown atomic state in a QED-cavity without Bell-state measurement via two-photon Jaynes–Cummings model in the effective Hamiltonian approach. This comment presents an alternative method, based on the so called 'full two-photon Jaynes–Cummings Hamiltonian approach'. Accordingly, it describes the evolution of the two-photon degenerate process for arbitrary average photon number inside the cavity, as the correct way to implement teleportation in this scenario.