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On the reduced density matrix for a chain of free electrons

Ingo Peschel
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Abstract

The properties of the reduced density matrix describing an interval of N sites in an infinite chain of free electrons are investigated. A commuting operator is found for arbitrary filling and also for open chains. For a half filled periodic chain it is used to determine the eigenfunctions for the dominant eigenvalues analytically in the continuum limit. Relations to the critical six-vertex model are discussed.

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Ingo Peschel. 2004-06-26. On the reduced density matrix for a chain of free electrons. https://doi.org/10.1088/1742-5468%2F2004%2F06%2Fp06004

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