1202.0383 (Masashi Orii et al.)

Quantum Entanglement of Tensor Networks with Symmetry Projections    [PDF]

Masashi Orii, Hiroshi Ueda, Isao Maruyama

We investigate the global-symmetry projections applied to the tensor network
states from the view point of the entanglement entropy and the mutual
information. The projections to the translational invariant space and to the
total-$S^z$-zero space give logarithmically increasing mutual information with
respect to the system size. In the anti-ferromagnetic $S=1/2$ Heisenberg chain
and lattice, the optimized energies become accurate numerically by using
variational states of the projected tensor network states, because the
projections reflecting symmetries of the ground states generate quantum
entanglement.

View original: http://arxiv.org/abs/1202.0383