On the reduced density matrix for a chain of free electrons
arXiv:cond-mat/0403048 · doi:10.1088/1742-5468/2004/06/P06004
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.
8 pages, small changes, Equ.(24) corrected, final version