The magnetization process of the S=1/2 delta chain with the anisotropic ferromagnetic interaction is investigated using the numerical diagonalization of finite-size clusters. It is found that the spin nematic liquid phase appears in higher magnetization region, as well as the SDW liquid one in lower region.
Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy 65(5) 243-248 2018年 査読有り
The S = 1/2 Heisenberg antiferromagnet on the Lieb lattice accompanied by frustrating interactions is studied by the numerical-diagonalization method. Numerical results suggest that the model of the lattice obtained by combination of the Lieb lattice and the square lattice shows nontrivial states with nonzero spontaneous magnetization smaller than one third of the saturation magnetization when the strength of the frustrating interaction is in a specific region. In the region, the spontaneous magnetization gradually changes by varying the strength of the frustration. We find that the quantum effect in frustrating interactions is related to the appearance of the phase in which such weak spontaneous magnetizations occur.