The Preparation Of Multi-particle Entangled State Via Quantum Zeno Dynamics And Transitionless Quantum Driving

The entangled state,which is the most important consept in the quantum mechanics,is widely used to all fields in quantum information,where it plays the role of the important carrier and coenerstone.So the preparation of quantum entangled state is an essential requisite in the quantum information,the research of the preparation of quantum entangled state is a key issue in quantum information.In the all entangled states,we pay attention to the maximally multi-particle entangled state,because they show more nonclassical effects.But the more particles that are entangled,the more difficultly we prepare the entangled state.In the recent years,many efforts are done in many quantum systems.Among those systems,the cacity QED system has a favourable prospect and acts as an important tool in modern quantum research.It attracts much attention.In the article,we mainly study the preparation of maximally multi-particle entangled state via quantum Zeno dynamics and transitionless quantum driving in cavity QED system.The details of this article are as follows:In Chaper 1,we introduce the concept of quantum entanglement and two kinds of maximally entangled states.We also introduce the concept of cavity QED,fiber-cavity coupling and the Jaynes-Cummings modal in the cavity QED.At last,we briefly summarize our research emphasis and the main content of the article.In Chapter 2,we briefly introduce the dynamical method during the process of the preparation of the entangled state.We mainly introduce quantum Zeno dyanmics,transitionless quantum driving and adiabatic passage,especially STIRAP.In addition,another method to construct shortcuts to adiabatic passage,Lewis-Riesenfeld theory,is also presented to understand shortcuts to adiabatic passage better.At last,we introduce a useful method called time-averaged dynamics,which is used to obtain the effective Hamiltonian for detuned quantum system.In Chapter 3,we aim to prepare the maximally multi-particle entangled state in separate coupled cavities via quantum Zeno dynamics.The scheme also makes use of fiber-cavity system and the large detuning condition.In the scheme the number of the entangled particles is variable.The results of numerical simulation show that the scheme is robust against the optical fibers decay.In Chapter 4,by making joint use of quantum Zeno dynamics and the approach of transitionless quantum driving to construct shortcuts to adiabatic passage,we propose a scheme to fast generate maximally multi-particle entangled state and in the scheme the number of the entangled particles is variable.What is important is that we successfully construct the additional Hamilton in the present system,because the additional Hamilton is often inexistent.In additon,we compare shortcuts to adiabatic passage with adiabatic passage.The result shows that the former is not only faster than the latter,but also the former can reach the same fidelity as the latter.Finally,we summarize the whole article in some words at the end of the article.