Research On Three-dimensional Entanlement And Quantum Exchange Gate Generated By Rydberg Atoms

The Rydberg atom is a class of neutral atoms in a highly excited state where the main quantum number is particularly large compared to the normal neutral atom.It has a long lifetime,a large radius,a strong electric dipole moment,and some properties that other neutral atoms don't have.The Rydberg atom dipole dipole interaction can also induce a blocking effect in the Rydberg state.This blocking effect means that,on the order of a micron,there is at most one atom that can excite a large number of the Rydberg states.This blocking effect is the theoretical basis of many quantum manipulation schemes.Therefore,the interaction intensity between Rydberg atoms can be adjusted flexibly in physics to realize the operation of various high-fidelity quantum gates and the preparation of different entangled states in quantum.When the relationship between the Rydberg interaction intensity and the atomic transition frequency is satisfied,the atoms can also be excited by the Rydberg state,which leads to the so-called Rydberg lock.In this paper,we focus on a scheme to generate three-dimensional entanglement between two Rydberg atoms by applying two laser fields to drive two transitions of each atom.The blocking and anti-blocking properties of Rydberg atoms are introduced in detail,and a scheme of generating three-dimensional entanglement between two Rydberg atoms is proposed,that is,two laser fields are applied to drive two transitions of each atom.By introducing a dissonance compensation to offset the stark shift,an effective resonant three-level system is created.First,four three-dimensional entangled states are calculated,and four three-dimensional entangled states involving |00>,|11>and|rr>are theoretically calculated and numerically recognized.Then,the effects of RRI strength variation and atomic space fluctuation on the scheme are discussed.The effect of Rydberg spontaneous emission on the generation of 3d entanglement is studied.Rabi frequency is analyzed to ensure the generation of high-fidelity 3d entanglement.Finally,the numerical search algorithm is given to obtain the optimized parameters,shorten the operation time and reduce the decoherence accumulation.Quantum gate operations can also be performed for Rydberg atoms.We propose a scheme to create a quantum exchange gate between two Rydberg atoms.We apply two laser field to drive two of each atom transition.First of all,we exchange the second atom laser driver,the transition of the Rabi frequency ?1'drive(?)red as mismatch ?1,drive(?)frequency for ?2,for the blue detuning ?2 Then,the detuning compensation method is used to eliminate the stark shift,so as to produce an effective resonant three-level system and to realize the research of quantum exchange gate and its corresponding quantum exchange gate.It is found that for high fidelity exchange gates F?0.99,the absolute deviation value of the interaction intensity between atoms should be limited to less than 50kHz.