DIPOLE SQUEEZING IN THE MULTIPHOTON JAYNES-CUMMINGS MODEL WITH AND WITHOUT THE ROTATING-WAVE APPROXIMATION

By virtue of the numerical method of Graham and Hohnerbach [12], we ha ve investigated the quantum fluctuations of the atomic dipole variable s in the multi-photon Jaynes-Cummings model with and without the rotat ing wave approximation (RWA) when it is restricted to the following in itial condition: the atom in its superposition state and the field in the vacuum state. We found that even under the conditions in which the RWA is considered to be valid there are significant effects of virtua l-photon field on dipole squeezing predicted in the RWA, and dipole sq ueezing turns to disappear for sufficiently strong coupling.