Entropy estimates for finitely correlated states

authored by

M. Fannes, B. Nachtergaele, R. F. Werner

Abstract

We study in this paper the Renyi entropy densities of integer order for the class of finitely correlated states on a quantum spin chain, and obtain in this way explicit lower bounds for the usual entropy density. We apply this technique to obtain good bounds on the entropy density of a certain state on a spin-3/2 chain. This state is a ground state of a translation invariant nearest neighbour SU(2)-invariant interaction, which is thus shown to posses a residual entropy as T . Breaking the translation symmetry by adding a small SU(2)-invariant interaction of period two removes the ground state degeneracy, and produces a non-zero spectral gap above the ground state.

Organisation(s)

Institute of Theoretical Physics

Type

Article

Journal

Ann. Inst. H. Poincaré Phys. Théor.

Volume

57

Pages

259-277

No. of pages

19

Publication date

1992

Publication status

Published

Peer reviewed

Yes