Quantum Speed Limit,Coherence And Population Trapping Of Qubit System In Dissipative Cavity

In this paper,quantum coherence,quantum speed limit and population trap-ping of a qubit system are investigated in a dissipative cavity.The results show that the quantum speed limit,quantum coherence and the population trapping of the qubit system can be effectively controlled by quantum regulating technology.The main contents are as follows:1.The background,significance and the basic theory of research on the quantum speed limit,quantum coherence and population trapping are introduced briefly.2.The quantum speed limit of a qubit system in a dissipative cavity is stud-ied.The results show that the quantum speed limit time depends on the atomic initial state,the atom-cavity coupling constant and the non-Markovian effect.The quantum speed time is shorter increase when the atom-cavity coupling constant is lager,but the cavity-environment coupling has little effect on the quantum speed time.3.Quantum coherence and non-Markovianity of an qubit in dissipative cavity under weak measurement are investigated.The results show that the quantum coherence obviously depends on the atomic initial state,the strength of the weak measurement and its reversal,the atom-cavity coupling constant and the non-Markovian effect.The stronger the atom-cavity coupling and the non-Markovian effect,the quantum coherence is preserved more efficiently.Finally,a physical explanation of the quantum coherent dynamics of the qubit is given by using the non Markovianity of the environment.4.Population dynamics of excited atoms in dissipative cavities is investigated.The results show that the regeneration and trapping of the excited state can be realized by controlling the atom-cavity coupling and the non Markovian effect for different initial states.The stronger the atom-cavity coupling or the non-Markovian effect,the more regeneration number and the better trapping of the excited state.5.A summary and outlook is presented.