Comb entanglement in quantum spin chains

dc.creatorKeating, J. P.
dc.creatorMezzadri, F.
dc.creatorNovaes, M.
dc.date2006-04-04
dc.date.accessioned2026-07-07T08:47:03Z
dc.date.available2026-07-07T08:47:03Z
dc.descriptionBipartite entanglement in the ground state of a chain of $N$ quantum spins can be quantified either by computing pairwise concurrence or by dividing the chain into two complementary subsystems. In the latter case the smaller subsystem is usually a single spin or a block of adjacent spins and the entanglement differentiates between critical and non-critical regimes. Here we extend this approach by considering a more general setting: our smaller subsystem $S_A$ consists of a {\it comb} of $L$ spins, spaced $p$ sites apart. Our results are thus not restricted to a simple `area law', but contain non-local information, parameterized by the spacing $p$. For the XX model we calculate the von-Neumann entropy analytically when $N\to \infty$ and investigate its dependence on $L$ and $p$. We find that an external magnetic field induces an unexpected length scale for entanglement in this case.
dc.description6 pages, 4 figures
dc.identifierhttps://arxiv.org/abs/quant-ph/0604016
dc.identifierhttp://arxiv.org/abs/quant-ph/0604016
dc.identifierPhys. Rev. A 74, 012311 (2006)
dc.identifierdoi:10.1103/PhysRevA.74.012311
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/143464
dc.subjectQuantum Physics
dc.titleComb entanglement in quantum spin chains
dc.typetext

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