The Preparation And Detection Of Dicke State On Trapped Ions

Entanglemen is not only a very important part of quantum information science, but also one of the most prominent and interesting features of quantum mechanics. It is also a critical resource and a very wide range of applications. So, for the preparation of quantum entanglement, preparation of quantum entangled states and entanglement detection is one of the most critical. Quantum entanglement is often used in quantum dense coding, quantum teleportation, quantum secret sharing, quantum communication, quantum computation and so on. It is played a leading role in the field of quantum information science. The main content of this paper is based on the ion trap system, this paper is proposing two schemes to prepare symmetric Dicke states of arbitrary bits and entanglement detection of Dicke states in the dark state evolution of adiabatic passage.This paper is divided into four chapters. The background and theoretical basis of the study are put in the first chapter, which includes the basic knowledge of quantum bits, quantum entanglement, pure state and mixed state and entanglement measure. The second chapter, we introduced some basic characteristics and three kinds of schemes for the preparation about Dicke state, via cross Kerr nonlinear effect, through STIRAP using multi phonon excitation and the adiabatic evolution of channel preparation of arbitrary qubit symmetric Dicke state, respectively. Here, we propose that the third preparation schemes have more advantages compared to the former two schemes in particularly, which are more beneficial to the preparation of the experiment. The third chapter is some of our own work, first of all a rough introduction to the significance of the detection of entangled states. Secondly, a scheme in ion trap system combined with adiabatic evolution of dark state detection entangled Dicke state is introduced. The scheme tells us in a mixture of Dicke state how to distinguish containing determine exciton number of target Dicke state. And for the multi particle system, we can also apply this entanglement detection scheme technology to it. Our scheme is robust to imperfect factors such as detector dissipation, mismatch of experiment parameters, and detector inefficiency, for the fidelity of the Dicke state is guaranteed, for specific experiments process is particularly important practical significance. At the end of the paper, we briefly summarizes the work of this paper, and looks forward to the application of detection of entangled states in quantum information science and the future development.