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arXiv 1808.02589cond-mat.supr-concond-mat.str-el
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扩展哈伯德模型中的非常规超导:弱耦合重整化群

Unconventional superconductivity in the extended Hubbard model: Weak-coupling renormalization group

Sebastian Wolf, Thomas L. Schmidt, Stephan Rachel

摘要:

本文采用弱耦合重整化群方法研究了二维格点上扩展排斥哈伯德模型中出现的非常规超导相。排斥作用通常导致更高的角动量库珀配对。通过不仅考虑长程跳跃,而且考虑非局域电子-电子相互作用,我们能够找到正方形和六边形晶格上所有不可约表示的超导解,包括手征拓扑超导性的扩展区域。对于正方形,三角形和蜂窝状晶格,我们提供了详细的超导相图以及耦合强度量化相应的临界温度取决于能带结构参数,带填充,和相互作用参数。我们讨论了该方法的灵敏度相对于积分网格和修补方案的数值分辨率。最后,我们展示了如何有效地达到高数值精度。

英文摘要:

We employ the weak-coupling renormalization group approach to study unconventional superconducting phases emerging in the extended, repulsive Hubbard model on paradigmatic two-dimensional lattices. Repulsive interactions usually lead to higher-angular momentum Cooper pairing. By considering not only longer-ranged hoppings, but also non-local electron-electron interactions, we are able to find superconducting solutions for all irreducible representations on the square and hexagonal lattices, including extended regions of chiral topological superconductivity. For the square, triangular and honeycomb lattices, we provide detailed superconducting phase diagrams as well as the coupling strengths which quantify the corresponding critical temperatures depending on the bandstructure parameters, band filling, and interaction parameters. We discuss the sensitivity of the method with respect to the numerical resolution of the integration grid and the patching scheme. Eventually we show how to efficiently reach a high numerical accuracy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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