Naslov
Long-distance entanglement and quantum teleportation in XX spin chains

Autori
Campos Venuti, L. ; Giampaolo, S. M. ; Illuminati, F. ; Zanardi, P.

Izvornik
Physical review, A, Atomic, molecular, and optical physics (1050-2947) 76 (2007), 5; 052328, 9

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, ostalo

Ključne riječi
entanglement

Sažetak
Isotropic XX models of one-dimensional spin-1/2 chains are investigated with the aim to elucidate the formal structure and the physical properties that allow these systems to act as channels for long-distance, high-fidelity quantum teleportation. We introduce two types of models: 共i兲 open, dimerized XX chains, and 共ii兲 open XX chains with small end bonds. For both models we obtain the exact expressions for the end-to-end correlations and the scaling of the energy gap with the length of the chain. We determine the end-to-end concurrence and show that model 共i兲 supports true long-distance entanglement at zero temperature, while model 共ii 兲 supports “quasi-long-distance” entanglement that slowly falls off with the size of the chain. Due to the different scalings of the gaps, respectively exponential for model 共i 兲 and algebraic in model 共ii兲, we demonstrate that the latter allows for efficient qubit teleportation with high fidelity in sufficiently long chains even at moderately low temperatures.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA