Entanglement States in Ion Traps: Properties and Applications

Qinghong Liao, Jun-Fang Wu, Ping Wang

Azam Anbaraki, Davood Afshar, Mojtaba Jafarpour

Liu Wang-Yun, BI Si-wen, Xi-bo Dou +1 more

The time evolution properties of the field quantum entropy in the system of a trapped ion interacting resonantly with a standing-wave laser field is studied by utilizing the Von Neumann reduced quantum entropy theory, and our attention focuses on the discussion of the influence of the Lamb-Dick parameter, the position of the ion in the standing-wave laser field and the initial state of the trapped ion on the evolution properties of the field quantum entropy. The results obtained from the numerical calculation indicate that: the value of the Lamb-Dick parameter effect the oscillation frequency and amplitude of the quantum entanglement between the trapped ion and the standing-wave laser field, the larger the Lamb-Dick parameter is, the weaker the average entanglement level between the ion and the field will be. When moving the tapped ion from the node of the standing-wave laser to the loop, the vibration frequency of the quantum entanglement between the field and the ion becomes slow gradually, and the entanglement degree gets weaker and weaker. With the decrease of the probability of the trapped ion being in the excited state, the quantum entanglement between the trapped ion and the stanging-wave laser field shows the tendency of increase first and then decrease. These properties have certain reference value for the preparation of entangled states and for the quantum communications with the thapped ion, and so on.

Xue Li, Shou-Sheng Huang, Lie Wu +2 more

This paper proposes a scheme to generate, in an ion-trap, a type of multipartite maximally entangled state which was first introduced by Chen et al . [Chen P X, Zhu S Y and Guo G C 2006 Phys. Rev . A 74 032324 ]. The maximum entanglement property of these states is examined. It also demonstrates how to discriminate among these states in the ion-trap.

Christoph Becher, Jan Benhelm, D. Chek-al-kar +16 more

Xin-Wen Wang, Guojian Yang

Recently, a genuine four-qubit entangled state ${\ensuremath{\mid}{\ensuremath{\chi}}^{00}⟩}_{3214}$ has been proposed [Y. Yeo and W. K. Chua, Phys. Rev. Lett. 96, 060502 (2006)]. This state has many interesting entanglement properties and possible applications in quantum information processing and fundamental tests of quantum physics. Here we present a simple scheme for generating such a state in an ion-trap system. We also demonstrate how to discriminate between the 16 basis states ${{\ensuremath{\mid}{\ensuremath{\chi}}^{ij}⟩}_{3214}={\ensuremath{\sigma}}_{3}^{i}{\ensuremath{\sigma}}_{1}^{j}{\ensuremath{\mid}{\ensuremath{\chi}}^{00}⟩}_{3214},i,j=0,1,2,3}$.