Abstract

Projector Quantum-Monte-Carlo method is used to examine effects of spin ordering on superconducting correlations in the two dimensional spin-one-half Falicov-Kimball model with Hund and Hubbard coupling. At first, the ground state spin configurations of the model are determined for a wide range of model parameters like the d-electron filling N_d, the Hund coupling J_z, the Hubbard coupling U, and then the average vertex correlation functions, as a measure of the superconducting correlations in these ground states, are calculated. It is found that the presence of the fully or partially developed antiferromagnetic spin ordering in the ground state dramatically enhances superconducting correlations in the d-wave channel, while the ferromagnetic spin substructures in the form of parallel/antiparallel domains, bands or lines superconducting correlations strongly suppress.

Graphical abstract

中文翻译：

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在具有Hund和Hubbard耦合的自旋二分之一的Falicov-Kimball模型中，通过自旋有序增强超导相关性：量子蒙特卡洛研究

摘要

投影机量子-蒙特卡洛方法用于检验自旋有序对具有Hund和Hubbard耦合的二维自旋二分之一Falicov-Kimball模型中超导相关性的影响。首先，针对各种模型参数（例如d电子填充N _d，Hund耦合J _z，Hubbard耦合U，然后平均顶点相关函数）确定模型的基态自旋配置，计算了这些基态中超导相关的测量值。发现在基态中存在完全或部分发展的反铁磁自旋有序可显着增强基体中的超导相关性。d波通道，而以平行/反平行磁畴，带或线超导相关形式出现的铁磁自旋子结构强烈抑制。

图形概要