A class of asymmetric gapped Hamiltonians on quantum spin chains and its characterization II

Abstract

We give a characterization of the class of gapped Hamiltonians introduced in PartI [O]. The Hamiltonians in this class are given as MPS (Matrix product state) Hamiltonians. In [O], we list up properties of ground state structures of Hamiltonians in this class. In this Part II, we show the converse. Namely, if a (not necessarily MPS) Hamiltonian $H$ satisfies five of the listed properties, there is a Hamiltonian $H'$ from the class in [O], satisfying the followings: The ground state spaces of the two Hamiltonians on the infinite intervals coincide. The spectral projections onto the ground state space of $H$ on each finite intervals are approximated by that of $H'$ exponentially well, with respect to the interval size. The latter property has an application to the classification problem.