Frustration-driven QPT in the 1D extended anisotropic Heisenberg model

By using Density Matrix Renormalization Group (DMRG) technique we study the 1D extended anisotropic Heisenberg model. We find that starting from the ferromagnetic phase, the system undergoes two quantum phase transitions (QPTs) induced by frustration. By increasing the next-nearest-neighbor (NNN) interaction, the ground state of the system changes smoothly from a completely polarized state to a NNN correlated one. On the contrary, letting the in-plane interaction to be greater than the out-of-plane one, the ground state changes abruptly.
Comment: 4 pages, 4 figures, to be presented at CSMAG-07 Kosice, Slovakia, July 2007