论文标题
无序的哈伯德链的随机单线样阶段
Random singlet-like phase of disordered Hubbard chains
论文作者
论文摘要
局部力矩的形成在无序的半导体（例如Si：p）中无处不在，在金属和绝缘状态下都可以观察到它。在这里，我们专注于无序绝缘体中的局部力矩行为，这是由短量的排斥电子电子相互作用引起的。使用密度矩阵重新归一化组和强鉴定重新归一化方法，我们研究了相互作用绝缘子的范式模型：具有淬火随机性的一维哈驼链。在具有随机的fermion跳或随机化学电位的链中，无论是在半填充时还是远离半填充，我们都会发现指数衰减和费米昂2点相关性，但是指示随机单圈相的自旋相关性的幂律衰减。可以通过吸引哈伯德链的大交互极限来定性地理解数值结果，其中出现了非常简单的图片。
Local moment formation is ubiquitous in disordered semiconductors such as Si:P, where it is observed both in the metallic and the insulating regimes. Here, we focus on local moment behavior in disordered insulators, which arises from short-ranged, repulsive electron-electron interactions. Using density matrix renormalization group and strong-disorder renormalization group methods, we study paradigmatic models of interacting insulators: one dimensional Hubbard chains with quenched randomness. In chains with either random fermion hoppings or random chemical potentials, both at and away from half-filling, we find exponential decay of charge and fermion 2-point correlations but power-law decay of spin correlations that are indicative of the random singlet phase. The numerical results can be understood qualitatively by appealing to the large-interaction limit of the Hubbard chain, in which a remarkably simple picture emerges.
