The fidelities of quantum states in the two-atom Tavis-Cummings model where the atoms are driven by an external classical field are derived. The influence of the external field and the dipole-dipole interaction of the atoms in a special initial state on the fidelity is discussd.
We study the properties of atoms and cavity field in the two-atom Tavis–Cummings model where the two atoms interact with each other and are also driven by an external classical field. We consider the special case that the cavity is initially in a coherent state. The atomic inversion, the average photons number and the Mandel parameter in the driven Tavis–Cummings model are given and analysed numerically. We pay special attention to the dynamical behaviour of the atoms and the cavity field modified by the external field.
The dipole-dipole interaction of the two atoms is discussed.By considering the in- teraction between the two-mode squeezing vacuum state field and the environment(atoms),we investigate the quantum information fidelities of the atoms the field and the system in two- mode squeezing vacuum state Tavis-Cummings model.With the help of the computer sim- ulation,the time evolution of fidelity of system,atoms and field is obtained.The result is indicate that r and k are important to the fidelity of the quantum information.When the two atoms are initially in the groud state,decreasing r can increase the three fidelities.On the contrary,when the two atoms are initially in one of the Bell states,increasing r can increase the three fidelites.
Average fidelities of quantum states in Tavis-Cummings model are studied by means of quantum theory.We consider the strongly coupled atom-field system as a quantum-classical hybrid with dynamically coupled quantum and classical degrees of freedom.The result shows the fidelities become higher with the increasing probability of two atoms initially situated in the ground state and the field in vacuum state.While the two atoms initially situated in ground state behave no-correlation and the field in vacuum state,the quantum state of all systems do not lose fidelities during evolution.
We study the interaction of the atoms in the two-atom Tavis-Cummings (T-C) model under an external classical driving field. The eigenenergies - quasienergies and eigenstates of the T-C system driven by the external field are calculated i n the interaction picture. We also give the general wave function of the system in the Schrdinger picture. We show that the driving field does not change the energy levels of the T-C model, but makes the Fock states displaced. A stationar y state with a definite frequency in the normal two-atom T-C model is transform ed into the Fock states with infinite frequencies by the driving field.
The quantum properties of atoms in double-atom Tavis-Cummings model with Gaussian atom-field coupling are studied.The influence of atomic motion perpendicularity to the axes of resonant cavity and initial states of the system on the atomic population inversion and double-atom dipole squeezing are analysed numerically.We find that the motion affects the collapse and revival of the atomic inversion,but it doesn't affect the maximun dipole squeezing.The maximun dipole squeezing can be got when the field is vacuum and the atoms are in some special entangled state at the begining.