Corrections to scaling for block entanglement in massive spin chains

Abstract

We consider the Rényi entropiesSn in one-dimensional massive integrable models diagonalizable by means of corner transfermatrices (such as Heisenberg and Ising spin chains). By means of explicit examples andusing the relation of the corner transfer matrix with the Virasoro algebra, we showthat close to a conformally invariant critical point, when the correlation lengthξ is finite but large, the corrections to the scaling are of the unusual formξ − x/n, withx the dimension of a relevant operator in the conformal theory. This is reminiscent of theresults for gapless chains and should be valid for any massive one-dimensional model closeto a conformal critical point.