Entanglement Perturbation Theory for Infinite Quasi-1D Quantum Systems

Abstract

We develop Entanglement Perturbation Theory (EPT) for infinite Quasi-1D quantum systems. The spin 1/2 Heisenberg chain with ferromagnetic nearest neighbor (NN) and antiferromagnetic next nearest neighbor (NNN) interactions with an easy-plane anisotropy is studied as a prototypical system. The obtained accurate phase diagram is compared with a recent prediction [Phys.Rev.B,81,094430(2010)] that dimer and Neel orders appear alternately as the XXZ anisotropy Delta approaches the isotropic limit Delta=1. The first and second transitions (across dimer, Neel, and dimer phases) are detected with improved accuracy at Delta\approx 0.722 and 0.930. The third transition (from dimer to Neel phases), previously predicted to be at Delta\approx 0.98, is not detected at this Delta in our method, raising the possibility that the second Neel phase is absent.

5 pages, 5 figures

References in corpus (7)

• Classical simulation of infinite-size quantum lattice systems in one spatial dimension
• Unconventional Neel and dimer orders in a spin-1/2 frustrated ferromagnetic chain with easy-plane anisotropy
• Entanglement perturbation theory for the elementary excitation in one dimension
• New method for the 3D Ising model
• New method for the quantum ground states in one dimension
• Entanglement perturbation theory for the quantum ground states in two dimensions
• Entanglement Perturbation Theory for Antiferromagnetic Heisenberg Spin Chains

Cited by in corpus (1)

• Quantum Dimensional Transition in Spin-$\frac{1}{2}$ Antiferromagnetic Heisenberg Model on A Square Lattice and Space Reduction in Matrix Product State