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arXiv 2408.15933cond-mat.supr-con
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基于微观方法研究孪晶面上超导性的增强与抑制问题

A microscopic approach to the problem of enhancement and suppression of superconductivity on twinning planes

Anton Talkachov, Sahal Kaushik, Egor Babaev

AI总结:

本文用微观方法研究双晶界对超导临界温度的影响,发现纯几何效应即可导致临界温度的增强或抑制,并揭示了二维和三维晶格中不同相图特征的物理机制。

摘要:

使用微观方法,我们重新审视了存在双晶界时的超导临界温度变化问题。我们表明,临界温度的增强和抑制均可纯粹源于几何效应。这包括电子在这些晶体缺陷上的散射效应,即使耦合常数保持不变。我们考虑了具有在位s波超导配对、最近邻和次近邻跃迁的二维矩形晶格和三维体心立方晶格。在所考虑的含双晶界的二维晶格中,与孪晶面相关的超导临界温度在中等能带填充下受到抑制,而在几乎空/满的能带中得到增强。三维晶格的超导相图更为多样,这是由van Hove奇点、配位数变化以及与最近邻和次近邻距离的改变相互交织造成的。

英文摘要:

Using a microscopic approach, we revisit the problem of superconducting critical temperature change in the presence of twin boundaries. We show that both critical temperature enhancement and suppression can come purely from geometric effects. These include aspects of scattering of electrons on these crystalline defects even when the coupling constant is unchanged. We consider two dimensional rectangular and three dimensional body centered cubic lattices with onsite s-wave superconducting pairing, nearest and next-to-nearest neighbor hoppings. In the considered two dimensional lattice with twin boundaries, the superconducting critical temperature associated with twinning planes is suppressed for moderate band filling and enhanced for an almost empty/filled band. The superconducting phase diagram is more diverse for the three dimensional lattice, which is caused by the interplay of van Hove singularity, changing coordination number, and modification of distances to nearest and next-to-nearest neighbors.

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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