Density Matrix Renormalization Group Studies of Quasi One-Dimensional Systems

该研究人员计划利用White开发的密度矩阵重整化群（DMRG）研究在某些高温铜超导体的中子散射实验中观察到的空穴和自旋模式“条纹”。PI计划在16x8大小的掺杂t-J阶梯系统上进行大量的“数值实验”，旨在回答以下问题：条纹沿其长度是否具有强超导配对相关性？在什么情况下条纹会出现在二维空间中？在低掺杂情况下，条纹的自然线孔密度是多少？双鞋在条纹间穿有多容易？对隧穿是否大大增强了对？条纹是相互吸引还是相互排斥？条纹状态下的费米表面是什么样子的？（1,1）条是稳定的吗？PI计划增强DMRG并开发一种计算动态量的方法。此外，扩展到三波段哈伯德模型和一维耦合电子-声子系统是计划与应用DMRG有机导体的目的。该奖项涉及对材料的电子特性的研究，其中强电子-电子相互作用是重要的。这项工作的重点是高温超导体和相关材料。PI开发的一种有望取得重大进展的方法将在该项目中使用和改进，该项目包含强大的计算组件和算法开发。

9870930 White This investigator plans to study `stripes' which are patterns of holes and spins observed in neutron scattering experiments in some high temperature cuprate superconductors using the density matrix renormalization group (DMRG) developed by White. The PI plans a large number of "numerical experiments" on doped t-J ladder systems as large as 16x8 that are aimed to answer questions such as: Does a stripe have strong superconducting pairing correlations along its length? At what dopings do stripes appear in two dimensions? At low doping, what is the natural linear hole density of a stripe? How easily do pairs tunnel between stripes? Does pair tunneling greatly enhance pairing? Do stripes attract or repel each other? What does the Fermi surface look like in a striped state? Are (1,1) stripes stable? The PI plans to enhance the DMRG and develop a method for calculating dynamical quantities. Also extensions to three band Hubbard models and one dimensional coupled electron- phonon systems is planned with the aim of applying the DMRG to organic conductors. %%% This award involves research on electronic properties of materials in which strong electron-electron interactions are important. The focus of this effort is on high temperature superconductors and related materials. A method developed by the PI that holds promise for significant advance will be used and refined in this project which contains strong computational components and algorithm development.