0 Se p 20 09 Entanglement of graph states up to 8 qubits

09 04 1 v 3 1 4 Se p 20 00 Entangled Rings

Consider a ring of N qubits in a translationally invariant quantum state. We ask to what extent each pair of nearest neighbors can be entangled. Under certain assumptions about the form of the state, we find a formula for the maximum possible nearest-neighbor entanglement. We then compare this maximum with the entanglement achieved by the ground state of an antiferromagnetic ring consisting of ...

ua nt - p h / 00 09 06 3 v 1 1 4 Se p 20 00 Entanglement of Formation of an Arbitrary State of Two Rebits ∗

We consider entanglement for quantum states defined in vector spaces over the real numbers. Such real entanglement is different from entanglement in standard quantum mechanics over the complex numbers. The differences provide insight into the nature of entanglement in standard quantum theory. Wootters [Phys. Rev. Lett. 80, 2245 (1998)] has given an explicit formula for the entanglement of forma...

ar X iv : 0 90 9 . 16 03 v 1 [ qu an t - ph ] 9 S ep 2 00 9 Entanglement of graph states up to 8 qubits

The entanglement of graph states up to eight qubits is calculated in the regime of iteration calculation. The entanglement measures could be the relative entropy of entanglement, the logarithmic robustness or the geometric measure. All 146 local inequivalent graphs are classified as three categories: the 2-colorable graphs, the non 2colorable graphs with identical upper LOCC entanglement bound ...

ar X iv : 0 70 4 . 20 87 v 2 [ qu an t - ph ] 2 7 Se p 20 07 The SLOCC invariant and the residual entanglement for n - qubits ∗

In this paper, we find the invariant for n-qubits and propose the residual entanglement for n-qubits by means of the invariant. Thus, we establish a relation between SLOCC entanglement and the residual entanglement. The invariant and the residual entanglement can be used for SLOCC entanglement classification for n-qubits. PACS numbers: 03.67.-a, 03.65.Ta, 89.70.+c

ua nt - p h / 05 09 21 8 v 1 3 0 Se p 20 05 N - qubit entanglement via the J 2 y - type collective interaction