Phase diagram of the two-dimensional Hubbard-Holstein model
Phase diagram of the two-dimensional Hubbard-Holstein model
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DOI：
10.1038/s42005-020-0342-2
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发表时间：
2019-10
影响因子：
5.5
通讯作者：
N. Costa;K. Seki;S. Yunoki;S. Sorella
中科院分区：
文献类型：
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作者：
N. Costa;K. Seki;S. Yunoki;S. Sorella
电子-电子和电子-声子相互作用在相关材料中起着重要的作用，是自旋、电荷和对关联的关键特征。因此，在这里，我们研究它们的影响，在强关联系统中进行无偏量子蒙特卡罗模拟在正方形晶格Hubbard-Holstein模型在半填充。研究了反铁磁性（AFM）和电荷密度波（CDW）之间的竞争和相互作用，建立了其丰富的相图。在AFM和CDW相之间的区域中，我们发现了超导配对相关性的增强，有利于（非局部）s波对。我们的研究揭示了过去文献中的不一致，特别是CDW在纯荷斯坦模型情况下的出现。
The electron–electron and electron–phonon interactions play an important role in correlated materials, being key features for spin, charge and pair correlations. Thus, here we investigate their effects in strongly correlated systems by performing unbiased quantum Monte Carlo simulations in the square lattice Hubbard-Holstein model at half-filling. We study the competition and interplay between antiferromagnetism (AFM) and charge-density wave (CDW), establishing its very rich phase diagram. In the region between AFM and CDW phases, we have found an enhancement of superconducting pairing correlations, favouring (nonlocal) s-wave pairs. Our study sheds light over past inconsistencies in the literature, in particular the emergence of CDW in the pure Holstein model case.