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arXiv · hep-th/0611057

Exact evaluation of density matrix elements for the Heisenberg chain

Jun Sato·Masahiro Shiroishi·Minoru Takahashi
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Abstract

We have obtained all the density matrix elements on six lattice sites for the spin-1/2 Heisenberg chain via the algebraic method based on the quantum Knizhnik-Zamolodchikov equations. Several interesting correlation functions, such as chiral correlation functions, dimer-dimer correlation functions, etc... have been analytically evaluated. Furthermore we have calculated all the eigenvalues of the density matrix and analyze the eigenvalue-distribution. As a result the exact von Neumann entropy for the reduced density matrix on six lattice sites has been obtained.

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Jun Sato, Masahiro Shiroishi, Minoru Takahashi. 2006-11-06. Exact evaluation of density matrix elements for the Heisenberg chain. https://doi.org/10.1088/1742-5468%2F2006%2F12%2Fp12017

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