Tomita Norikazu, Watanabe Shuji
Yamagata University, 1-4-12 Kojirakawa, Yamagata, 990-8560, Japan.
Phys Rev Lett. 2009 Sep 11;103(11):116401. doi: 10.1103/PhysRevLett.103.116401. Epub 2009 Sep 9.
Quantum fluctuations (QF's) in the two-dimensional Hubbard model are visualized by superposition of optimized nonorthogonal Slater determinants. In the half-filled system, QF's consist of rotational and translational motions of spinon-antispinon pairs, while in the lightly doped systems (delta=0.96), those motions of polarons form the QF's. It is shown that an attractive interaction works between two polarons, in the framework of a projected Hartree-Fock picture. At about 10% doping, the ground state has a stripe structure and QF's due to deviations from the uniform stripe. The present method gives the ground state energies comparable or in some cases superior to the variational Monte Carlo method with a Gutzwiller projection parameter.
通过优化的非正交斯莱特行列式的叠加来可视化二维哈伯德模型中的量子涨落（QF）。在半填充系统中，QF由自旋子 - 反自旋子对的旋转和平移运动组成，而在轻掺杂系统（δ = 0.96）中，极化子的那些运动形成了QF。结果表明，在投影哈特里 - 福克图景的框架下，两个极化子之间存在吸引相互作用。在大约10%的掺杂水平下，基态具有条纹结构，并且由于偏离均匀条纹而产生QF。本方法给出的基态能量与具有古兹维勒投影参数的变分蒙特卡罗方法相当，在某些情况下甚至更优。
