论文标题
在安德森 - 哈伯德模型中的两体金属绝缘体过渡
Two-body metal-insulator transitions in the Anderson-Hubbard model
论文作者
论文摘要
我们回顾了我们在两个相互作用粒子系统中安德森定位的最新结果，结合了接触相互作用。基于与有效的单粒子问题的精确映射，我们从数值上研究了两（2D）和三维（3D）无序晶格中对这对的金属 - 绝缘体相变的发生。在两个维度中，我们发现相互作用相对于其单粒子对应物会导致对成对定位长度的指数增强，但不会引起离域化过渡。特别是我们表明，先前对2D相互作用引起的安德森过渡的主张是强大尺寸效应的结果。在三个维度中，我们发现这对经历了属于非互动模型的相同（正交）普遍性类别的金属 - 绝缘体过渡。然后，我们探索能量E，无序W和相互作用强度U的相图，该相位揭示了丰富而违反直觉的结构，并具有多个金属和绝缘阶段。我们指出，这种现象源自以给定能量和无序强度可用的对态的分子和散射状态。
We review our recent results on Anderson localization in systems of two interacting particles coupled by contact interactions. Based on an exact mapping to an effective single-particle problem, we numerically investigate the occurrence of metal-insulator phase transitions for the pair in two- (2D) and three-dimensional (3D) disordered lattices. In two dimensions, we find that interactions cause an exponential enhancement of the pair localization length with respect to its single-particle counterpart, but do not induce a delocalization transition. In particular we show that previous claims of 2D interaction-induced Anderson transitions are the results of strong finite-size effects. In three dimensions we find that the pair undergoes a metal-insulator transition belonging to the same (orthogonal) universality class of the noninteracting model. We then explore the phase diagram in the space of energy E, disorder W and interaction strength U, which reveals a rich and counterintuitive structure, endowed with multiple metallic and insulating phases. We point out that this phenomenon originates from the molecular and scattering-like nature of the pair states available at given energy and disorder strength.
