论文标题
相关的狄拉克费米系统中稀释引起的中间相
An intermediate phase induced by dilution in a correlated Dirac Fermi system
论文作者
论文摘要
用非磁离子代替磁离子是研究稀释的一种新方法。使用行列式量子蒙特卡洛计算，我们研究了一个相互作用的dirac fermion模型，现场库仑排斥在分数$ x $上随机零。根据电导率，状态的密度和抗铁磁结构因子，我们的结果揭示了稀释和排斥之间的竞争引起的新型中间绝缘相。随着非磁离子的掺杂水平的增加，发现这种非磁性中间相可以从零温率的量子临界点出现，从而将金属和莫特绝缘阶段分开，其稳健性在广泛的相互作用中得到了证明。在密切相关的材料的前提下，我们建议掺杂非磁离子可以有效地将系统转换回传磁金属相。该结果不仅与稀释对磁性影响的实验相一致，而且还为重点介绍了蜂窝晶格（如材料）中的金属 - 绝缘体过渡提供了一个可能的方向。
Substituting magnetic ions with nonmagnetic ions is a new way to study dilution. Using determinant quantum Monte Carlo calculations, we investigate an interacting Dirac fermion model with the on-site Coulomb repulsion being randomly zero on a fraction $x$ of sites. Based on conductivity, density of states and antiferromagnetic structure factor, our results reveal a novel intermediate insulating phase induced by the competition between dilution and repulsion. With increasing doping level of nonmagnetic ions, this nonmagnetic intermediate phase is found to emerge from the zero-temperature quantum critical point separating a metallic and a Mott insulating phase, whose robustness is proven over a wide range of interactions. Under the premise of strongly correlated materials, we suggest that doping nonmagnetic ions can effectively convert the system back to the paramagnetic metallic phase. This result not only agrees with experiments on the effect of dilution on magnetic order but also provides a possible direction for studies focusing on the metal-insulator transition in honeycomb lattice like materials.
