Study Of Displacement Geometric Phase To Achieve Entanglement In Multi-Mode Cavity QED

In this paper, we researched some questions about the displacement operator and geometric phase with quantum theory, and the potential applications in quantum entanglement. Quantum entanglement as an important resource, it is widely used in quantum information and quantum computation. However, entanglement easily influenced by some parameters disturbances and decoherence, it is necessary to have the approach of overcoming the decoherence effects.Based on the characteristic or geometric properties of the geometric phase, it can avoid the impact of some local noise, which is very significance to build the fault-tolerant quantum gate and entanglement. Conventional geometric phase have to take additional actions to eliminate the dynamical phase in geometric quantum computation, which increase the complexities in the realization process. The quantum computation caused by unconventional geometric phase can simplify the procedure, and improve the fault-tolerant for the quantum logic gates. The study of geometric phase have significance in quantum information and quantum computation.In this article, based on the unconventional geometric phase shift, we discussed how to achieve high fidelity of the entanglement in the multi-mode cavity QED system. The main contents include three parts as follows:① Introduce the development of quantum information and quantum computation, the difficulties in the experiment of quantum computers on the current, and the basic concepts and basic principle including the development and promotion of the geometric phase, qubit and some basic quantum logic gates, the definition and application of entanglement.② Introduce some usual physical systems in quantum computation, focuses on the quantum theory of atoms and field interaction in cavity quantum electrodynamics. The contents of the unconventional geometric phase caused by the displacement operator related with the cavity QED.③ In cavity QED system, we propose a scheme for the two-qubit entangled by atoms interaction with the two-mode cavity, and assisted by a strong laser. We discussed the feasibility of achieving the entanglement caused by unconventional geometric phase in the case of ideal and dissipation. We found that our scheme can generate the best two-qubit entanglement of 100% fidelity in the case of dissipation, but the attenuation only affect the probability of the entanglement production. Our scheme is not sensitive to the environment, and it is significance for the achievement of entanglement in the experiment.