Information transfer and orthogonality speed via pulsed-driven qubit
  We investigate the transfer and exchange information between a single qubit system excited by a rectangular pulse. The dynamics of the system is treated within and outside rotating wave approximation (RWA). The initial state of the qubit plays an important role for sending information with high fidelity. Within RWA, and as the fidelity of the transformed information increases the exchange information with the environment increases. For increasing values of atomic detuning, the fidelity decreases faster and the exchange information has an upper limit. Outside RWA,the fidelity of the transformed information increases as one increases the perturbation parameter. However the exchange information is very high compared with that within RWA. The orthogonality speed of the travelling qubit is investigated for different classes of initial atomic state settings and field parameters. 
N. Metwally and S. S.Hassan
quant-ph