论文标题
超导体 - 绝缘体过渡的电荷激发
Charge excitations across a superconductor-insulator transition
论文作者
论文摘要
我们使用公正的计算方法的组合（即精确的对角色化和量子蒙特卡洛模拟），研究了有吸引力的蜂窝哈伯德模型（质量术语），在具有迷人的蜂窝哈伯德模型的基础状态下，在有吸引力的Honeycomb Hubbard模型的基础状态下研究了超导体 - 绝缘体的转变（SIT），即我们研究超导体 - 绝缘体转变（SIT），即使用公正的计算方法的结合，我们研究了超导体的转变（SIT）。我们探究了整个SIT的最低能量电荷激发的性质，并表明它们是骨的，如在正方形晶格中对同一模型的先前研究中所推断的（并在强相互作用的方向上显示）。增加交错的电势的强度导致了一个跨界，在这种跨界中，低能刺激在绝缘阶段让纤维基因兴奋。我们还表明，SIT属于3 $ d $ -XY的通用类，就像在Square Lattice对应物中一样。我们在这两个晶格几何形状中的鲁棒性支持我们的发现对坐在干净系统中的普遍性的期望。
We study the superconductor-insulator transition (SIT) in the ground state of the attractive honeycomb Hubbard model in the presence of a staggered potential (a mass term), using a combination of unbiased computational methods, namely, exact diagonalization and quantum Monte Carlo simulations. We probe the nature of the lowest-energy charge excitations across the SIT and show that they are bosonic, as inferred (and shown in the strongly interacting regime) in a previous study of the same model in the square lattice. Increasing the strength of the staggered potential leads to a crossover in which bosonic low-energy excitations give way to fermionic ones within the insulating phase. We also show that the SIT belongs to the 3$d$-XY universality class, like in its square lattice counterpart. The robustness of our results in these two lattice geometries supports the expectation that our findings are universal for SITs in clean systems.
