Deconfinement criticality in the spatially anisotropic triangular antiferromagnet with ring exchange

作者：Nishiyama Yoshihiro^*

来源：Physical Review B, 2009, 79(5): 054425.

DOI：10.1103/PhysRevB.79.054425

The spatially anisotropic triangular antiferromagnet is investigated with the numerical diagonalization method. As the anisotropy varies, the model changes into a variety of systems such as the one-dimensional, triangular, and square-lattice antiferromagnets. Taking into account such a geometrical character, we impose the screw-boundary condition, which interpolates smoothly the one- and two-dimensional lattice structures. Diagonalizing the finite clusters with N = 16,20,...,32 spins, we observe an intermediate phase between the valence-bond solid (VBS) and Neel phases. Suppressing the intermediate phase by applying the ring exchange, we realize a direct VBS-Neel transition. The simulation data indicate that the transition is a continuous one with the correlation-length critical exponent v = 0.80 (15). These features are in agreement with the deconfinement-criticality scenario advocated by Senthil and co-workers in the context of the high-temperature superconductivity.

• 出版日期2009-2