dorsal/arxiv
View SchemaComb entanglement in quantum spin chains
| Authors | J. P. Keating, F. Mezzadri, M. Novaes |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0604016 |
| URL | https://arxiv.org/abs/quant-ph/0604016 |
| DOI | 10.1103/PhysRevA.74.012311 |
| Journal | Phys. Rev. A 74, 012311 (2006) |
Abstract
Bipartite 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.
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"abstract": "Bipartite entanglement in the ground state of a chain of $N$ quantum spins\ncan be quantified either by computing pairwise concurrence or by dividing the\nchain into two complementary subsystems. In the latter case the smaller\nsubsystem is usually a single spin or a block of adjacent spins and the\nentanglement differentiates between critical and non-critical regimes. Here we\nextend this approach by considering a more general setting: our smaller\nsubsystem $S_A$ consists of a {\\it comb} of $L$ spins, spaced $p$ sites apart.\nOur results are thus not restricted to a simple `area law\u0027, but contain\nnon-local information, parameterized by the spacing $p$. For the XX model we\ncalculate the von-Neumann entropy analytically when $N\\to \\infty$ and\ninvestigate its dependence on $L$ and $p$. We find that an external magnetic\nfield induces an unexpected length scale for entanglement in this case.",
"arxiv_id": "quant-ph/0604016",
"authors": [
"J. P. Keating",
"F. Mezzadri",
"M. Novaes"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.74.012311",
"journal_ref": "Phys. Rev. A 74, 012311 (2006)",
"title": "Comb entanglement in quantum spin chains",
"url": "https://arxiv.org/abs/quant-ph/0604016"
},
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