Tripartite entanglement witnesses and entanglement sudden death

Abstract

I explore entanglement dynamics in a three qubit system comparing the ability of entanglement witnesses to detect tri-partite entanglement to the phenomenon of entanglement sudden death (ESD). Using a system subject to dephasing I invoke entanglement witnesses to detect tri-partite GHZ and W-type entanglement and compare the evolution of their detection capabilites with the evolution of the negativity, bi-partite concurrence, and tri-partite negativity. Interestingly, I find a state in which there is no concurrence or tri-partite negativity but there is entanglement. Finally, I utilize a three qubit quantum error correction (QEC) code to address how ESD affects the abilities of quantum error correction.

Symmetry restoring and ancilla-driven entanglement for ultra-cold spin-1 atoms in a three-site ring

“…Such a situation has been well described in [22,34]. In our model it can be achieved by putting J = K = 0 (alternatively J 0 = 0) to the general equations (29) and (32). In this subsection we are going to focus on the |Ψ 0 (0) initial states, although similar results can be obtained for |Ψ 1 (0) , too.…”

“…Our motivation arises from the fact that whereas the entanglement of pure bipartite systems is well understood, apparently the entanglement of pure tripartite quantum states is not a trivial extension of the entanglement of bipartite systems [29,30]. Some results concerning the entanglement of pure tripartite systems have been presented in [30][31][32] (and the references therein). In these papers it was shown that for such systems a new kind of entanglement which cannot be captured by the bipartite measurements can be detected.…”

Fusing imperfect photonic cluster states

“…Figure 2 plots a non-exhaustive group of entanglement measures on the constructed cluster states. A number of these measures go to zero (exhibit entanglement sudden death [19][20][21]) at the decoherence strengths identified above: p ¼ 0.7044, 0.8284.…”

Influence of Kerr Medium on Entanglement of Cascade-Type Three-Level Atoms and a Bimodal Cavity Field

“…Furthermore, being a measurement of entanglement, the residual entanglement represents a collective property of all the three-qubit and characterizes an essential three-qubit entanglement [15][16][17]. Several researchers [18][19][20] have proposed physically motivated postulates to characterize three-body entanglement measures. Li et al [21] researched the three-body entanglement in Tavis-Cummings model by calculating Akhtarshenas's concurrences.…”