Spin-liquid Phase in Spin-1/2 square J_1-J_2 Heisenberg Model: A Tensor Product State Approach

          @misc{ pirsa_PIRSA:12040102,
            doi = {10.48660/12040102},
            url = {https://pirsa.org/12040102},
            author = {Wang, Ling},
            keywords = {Condensed Matter},
            language = {en},
            title = {Spin-liquid Phase in Spin-1/2 square J_1-J_2 Heisenberg Model: A Tensor Product State Approach},
            publisher = {Perimeter Institute},
            year = {2012},
            month = {apr},
            note = {PIRSA:12040102 see, \url{https://pirsa.org}}
          }
          

Abstract

The ground state phase of spin-1/2 J1-J2 antiferromagnetic Heisenberg model on square lattice in the maximally frustrated regime (J2 ~ 0.5J1) has been debated for decades. Here we study this model by using a recently proposed novel numerical method - the cluster update algorithm for tensor product states (TPSs). The ground state energies at finite sizes and in the thermodynamic limit (with finite size scaling) are in good agreement with the state of art exact diagonalization study, and
the energy differences between these two studies are of the order of 0.001 J1 per site. At the largest bond dimension available D (D = 9), we find a paramagnetic ground state without any valence bond solid order in the thermodynamic limit in the range of 0.5 <= J2/J1 <= 0.6, which implies the emergence of a spin-liquid phase. Furthermore, we investigate the topologically ordered nature of such a spin-liquid phase by measuring a nonzero topological entanglement entropy.