论文标题
Lieb Grattice的无序哈伯德模型中的金属绝缘体过渡
Metal-insulator transition in the disordered Hubbard model of the Lieb lattice
论文作者
论文摘要
使用行列式量子蒙特卡洛法，我们研究了Lieb晶格的相互作用的Hubbard模型中的金属 - 绝缘体跃迁，其中系统表征了以费米级为中心的平坦带。通过选择合适的电子密度，我们确保相互作用符号问题可以提高结果的可靠性。发现疾病和现场库仑排斥相互作用会产生有趣的效果，从而诱导金属 - 绝缘体过渡，这在半填充的情况下是不可能的。在热力学极限中，费米能量的状态密度仍然是有限的，这表明该系统是安德森绝缘子而不是莫特绝缘子。此外，这种掺杂系统是顺磁性的，与铁磁性的半填充系统不同。
Using the determinant quantum Monte Carlo method, we investigate the metal-insulator transition in the interacting disordered Hubbard model of a Lieb lattice, in which the system characterizes the flat band centered at the Fermi level. By choosing suitable electron densities, we ensure the weak interaction sign problem to improve the reliability of our results. It is found that disorder and on-site Coulomb repulsive interaction produce interesting effects that induce the metal-insulator transition which is impossible in the half-filled case. The density of states at the Fermi energy is still finite in the thermodynamic limit, suggesting that the system is an Anderson insulator rather than a Mott insulator. Moreover, this doping system is paramagnetic, unlike the half-filled system, which is ferrimagnetic.
