论文标题
T-T'-J模型中的自旋动力学：动力学密度 - 矩阵重新归一化组研究
Spin Dynamics in the t-t'-J Model: Dynamical Density-Matrix Renormalization Group Study
论文作者
论文摘要
带有四个腿的孔掺杂的T-T'-J梯子的基态偏向于条纹电荷分布。已知来自条纹基态的自旋激发沿着腿方向（QX方向）在Q =（PI，PI）附近表现出不相关的自旋激发。然而，从Q =（0，pi）向Q =（0，pi）的外部分散强度很强，与无弹性中子散射（INS）实验不一致。由于这种不一致的动机，我们通过将晶格的几何形状从四腿（24x4）更改为矩形（12x8）形状，并使用M X n = 96个晶格位点的T-j模型，并使用动态密度基质重质化组来研究动力学自旋结构因子。我们发现，在12x8晶格中，外部色散的光谱重量较弱，并且与接近Q =（PI，PI）的激发能的降低，与INS数据一致。在12x8晶格中，即使在存在条纹电荷分布的情况下，也实现了不相称的自旋相关性的弱化。为了进一步研究与几何相关的自旋动力学，我们重点介绍了库酸酯超导体的最近共振的非弹性X射线散射（RIX）报道的方向依赖性自旋激发，并通过检查8x8 T-T'-J Square lattice来获得RIX的一致结果。
The ground state of a hole-doped t-t'-J ladder with four legs favors a striped charge distribution. Spin excitation from the striped ground state is known to exhibit incommensurate spin excitation near q=(pi,pi) along the leg direction (qx direction). However, an outward dispersion from the incommensurate position toward q=(0,pi) is strong in intensity, inconsistent with inelastic neutron scattering (INS) experiment in hole-doped cuprates. Motivated by this inconsistency, we use the t-t'-J model with m x n=96 lattice sites by changing lattice geometry from four-leg (24x4) to rectangle (12x8) shape and investigate the dynamical spin structure factor by using the dynamical density matrix renormalization group. We find that the outward dispersion has weak spectral weights in the 12x8 lattice, accompanied with the decrease of excitation energy close to q=(pi,pi), being consistent with the INS data. In the 12x8 lattice, weakening of incommensurate spin correlation is realized even in the presence of the striped charge distribution. For further investigation of geometry related spin dynamics, we focus on direction dependent spin excitation reported by recent resonant inelastic x-ray scattering (RIXS) for cuprate superconductors and obtain a consistent result with RIXS by examining an 8x8 t-t'-J square lattice.
