Dynamic Properties Of Entanglement In Quantum Chaos

The mid-20th century, people realized the quantum chaos importance, through to quantum chaos a series of research, the people had the understanding to quantum chaos's some characteristics. But, still had not been at present solved about quantum chaos's some fundamental question.Recent years's some research work discovered that in the characteristic has the chaos phenomenon in the quantum entanglement dynamics. Therefore, the quantum entanglement was considered that is a quantum chaos characteristic, between the two has nature of the relations.Because entanglement is the quantum mechanics core as well as quantum information origin, therefore in the quantum chaos system's entanglement may provide one effective method as the research quantum chaos.The researchers study the quantum entanglement through many methods, including the linear entropy, decoherence and so on, also has through the quantum entanglement and the quantum Spin Squeezing, the quantum chaos relations studies the quantum entanglement.Spin Squeezing the same quantum entanglement equally is also one kind of classical quantum property indeed, therefore, the quantum chaos, the quantum entanglement and the quantum spin squeezing dynamics compressed nature of the inherent .This article uses the classical approximation the Dicke model and the QKT model , takes the research quantum chaos the typical model. By changing the position of different regions in the phase space, namely corresponds to the different quantum initial state, Using this kind of classics and quantum corresponding relationships to study nature of entanglement and spin squeezing. Prime task including the following two aspects:1. In the condition of classical limit, quantized Dicke model shows the dynamical behaviors of quantum chaos. The numerical calculation shows that there are some particular positions in the classical phase-space on which the quantum chaos is present. The impact of initial condition of these particular positions on entanglement of the model is analyzed both under RWA(rotating-wave approximation) and non-RWA. The evolutionary characteristics of the overall dynamics are studied in the phase-space as all phase points are considered to be the initial condition. There comes the conclusion that classical chaos will accelerate the generation of entanglement.2.In this paper a very typ ical QKT model in the quantum chaos has been discussed, and the properties of spin squeezing in the quantum chaotic system has been studied. The relation between spin squeezing parameters and chaotic parameter in the two different definitions is worked out by numerical calculation.The stronger that the regular regions are than chaotic ones, which are chosen firstly, in the classical phase space, the stronger the sp in system which the initial states locate at the centre of ellip tical regions as a result.If the initial states are chosen another condition, the contrary result is obtained naturally. It indicates the spin squeezing is very sensitive to the classical chaos and the classical chaos supp resses the spin squeezing. It is interesting that the definition by W ineland ismore sensitive than the one by Kitagawa and Ueda, consequently a conclusion, which the quantum chaos can be described by spin squeezing, is acquired.