Preparation Of The Maximum Entangled States Of Rydberg Atom Using Periodic Pump Dissipation

At the beginning of the 20 th century,the emergence of quantum mechanics marked the transition of the world from classical physics to quantum physics.With the vigorous development of science and technology,quantum physics has also extended to many branches,such as quantum optics,quantum field theory,quantum information and so on.Many concepts in the quantum field have also attracted a lot of interest,such as Entanglement,it.It plays an important role in quantum computation,quantum teleportation,quantum communication and quantum key distribution.It also has very good development potential.This paper mainly includes the following contents :Firstly,we briefly introduce several schemes for preparing quantum entanglement through unitary dynamics and dissipative dynamics in the past few years,and in order to select the carrier for preparing entanglement in this work,we investigate the Rydberg atoms compared with other physical systems.Compared with other physical systems,it has excellent characteristics such as easy arrangement in space,long energy level life,long-range strong Rydberg interaction,etc.,and decided to choose it as the operating object.Secondly,we find that although the two-dimensional and three-dimensional entanglement of the two atoms can be prepared in the scheme based on the continuous drive Unconventional Rydberg pumping combined with dissipation proposed by the previous researchers,there are mutual constraints between the physical parameters and the dissipation is very small.Finally,in order to solve the disadvantages of the continuous driving mechanism,we propose our own scheme.The coherent pumping and dissipative dynamics involved in the continuous driving scheme are divided into three parts to form a cycle.The first part is the single photon transition process from the atomic ground state to the excited state provided by the Unconventional Rydberg pumping.In the second part,the spontaneous emission rate from the Rydberg state to the ground state is accelerated by introducing an external classical field to couple the Rydberg state with a shorter lifetime optical state;in the third part,the atomic population is adjusted by the microwave coupling between the ground states.After several cycles,the two-dimensional and three-dimensional maximally entanglement of the two atoms with high fidelity can be finally realized.The innovation of this paper : Compared with the continuous driving scheme,because the three processes of classical field,controlled dissipation and microwave field are carried out independently,the parameters will not restrict each other.Therefore,as long as the parameters in each process can be arbitrarily adjusted within the allowable range of the experiment,the time required to prepare the entangled state can be greatly reduced.We also study the robustness of entanglement fidelity under periodic modulation scheme.When the Gaussian waveform pulse is introduced to replace the flat pulse,the robustness of the fidelity under time error can be further optimized.