Controlling Single-Particle Coherence and Spin Squeezing with Stimulated Raman Transition

We present a scheme for controlling single-particle coherence and spin squeezing of atom-photon with stimulated Raman transition. Here we are focus on the dependence of spin squeezing parameter on the mean photon number. We first derive the effective Hamiltonian and then obtain the analytical solution for state vector, the single-particle coherence and spin squeezing parameter. The stronger spin squeezing can be created by adding the mean photon number.