Comb entanglement in quantum spin chains

JP Keating, F Mezzadri, M Novaes

Research output: Contribution to journalArticle (Academic Journal)peer-review

16 Citations (Scopus)


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 noncritical regimes. Here we extend this approach by considering a more general setting: our smaller subsystem S-A consists of a comb of L spins, spaced p sites apart. Our results are thus not restricted to a simple area law, but contain nonlocal information, parametrized by the spacing p. For the XX model we calculate the von Neumann entropy analytically when N ->infinity 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.
Translated title of the contributionComb entanglement in quantum spin chains
Original languageEnglish
Pages (from-to)1 - 6
Number of pages6
JournalPhysical Review A: Atomic, Molecular and Optical Physics
Volume74 (1, 012311)
Publication statusPublished - Jul 2006

Bibliographical note

Publisher: American Physical Society
Other identifier: IDS number 069DK


Dive into the research topics of 'Comb entanglement in quantum spin chains'. Together they form a unique fingerprint.

Cite this