2014/03/31 by John Cardy, Christopher P. Herzog · 1 citation
Physics and Astronomy · #cond-mat.other #hep-th #quant-ph
paper · pdf · doi:10.1103/physrevlett.112.171603
published as Phys. Rev. Lett. 112, 171603 (2014) · 5 pages, 1 figure; v2 minor clarifications added, to appear in PRL
arxiv created 2014/04/14 · arxiv updated 2014/05/07
We consider single interval Rényi and entanglement entropies for a two dimensional conformal field theory on a circle at nonzero temperature. Assuming that the finite size of the system introduces a unique ground state with a nonzero mass gap, we calculate the leading corrections to the Rényi and entanglement entropy in a low temperature expansion. These corrections have a universal form for any two dimensional conformal field theory that depends only on the size of the mass gap and its degeneracy. We analyze the limits where the size of the interval becomes small and where it becomes close to the size of the spatial circle.