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Logarithmic divergence of the block entanglement entropy for the ferromagnetic Heisenberg model

Vladislav Popkov·Mario Salerno
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Abstract

Recent studies have shown that logarithmic divergence of entanglement entropy as function of size of a subsystem is a signature of criticality in quantum models. We demonstrate that the ground state entanglement entropy of $ n$ sites for ferromagnetic Heisenberg spin-1/2 chain of the length $L$ in a sector with fixed magnetization $y$ per site grows as ${1/2}\log_{2} \frac{n(L-n)}{L}C(y)$, where $C(y)=2\pi e({1/4}-y^{2})$

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Vladislav Popkov, Mario Salerno. 2004-04-05. Logarithmic divergence of the block entanglement entropy for the ferromagnetic Heisenberg model. https://doi.org/10.1103/physreva.71.012301

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