TY  - JOUR
A1  - de Beaudrap, Niel
A1  - Ohliger, Matthias
A1  - Osborne, Tobias J.
A1  - Eisert, Jens
T1  - Solving frustration-free spin systems
N2  - We identify a large class of quantum many-body systems that can be solved exactly: natural frustration-free spin-1/2 nearest-neighbor Hamiltonians on arbitrary lattices. We show that the entire ground-state manifold of such models can be found exactly by a tensor network of isometries acting on a space locally isomorphic to the symmetric subspace. Thus, for this wide class of models, real-space renormalization can be made exact. Our findings also imply that every such frustration-free spin model satisfies an area law for the entanglement entropy of the ground state, establishing a novel large class of models for which an area law is known. Finally, we show that our approach gives rise to an ansatz class useful for the simulation of almost frustration-free models in a simple fashion, outperforming mean- field theory.
Y1  - 2010
UR  - http://prl.aps.org/
U6  - https://doi.org/10.1103/Physrevlett.105.060504
SN  - 0031-9007
ER  -