arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.03117cond-mat.supr-concond-mat.str-el
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用最小实空间\emph{d}波对算符研究空穴掺杂三带\emph{d-p}模型的超导性质

Superconducting properties of the hole-doped three-band \emph{d-p} model studied with minimal-size real-space \emph{d}-wave pairing operators

A. Biborski, M. Zegrodnik, J. Spalek

摘要:

本文用变分蒙特卡罗(VMC)方法研究了三带\emph{d-p}模型,波函数采用BCS型,并辅以Gutzwiller和Jastrow修正子。VMC优化得到了具有空穴掺杂$δ\lesssim 0.4$序参量特征的圆顶状的$d$ - $wave$超导态,与实验观察结果吻合较好.此外,在VMC中计算的非对角对-对相关函数证明了最近在Gutzwiller波函数方法(DE-GWF)的图解扩展中获得的结果[cf. Phys. Rev. B \textbf{99},104511(2019)]。随后,通过最近提出的\emph{minimal-size real-space d-wave pairing operators} [Phys. Rev. B \textbf{100},214502(2019)]研究了$d$-$wave$配对的性质。通过分析相应的非对角对-对关联函数,报道了$d$和$p$轨道的长程超导有序的出现。证实了\emph{d-wave}在$d$轨道上的优势配对特征。此外,试探波函数被用来研究系统的磁性。自旋-自旋相关函数的分析进行,并显示反铁磁$\mathbf{q}=(π,π)$,短程有序,如预期的。为了完整起见,已经估计了电荷间隙,其对于母体化合物取值$Δ_{CG}\approx1.78\pm0.51\text{ eV}$,并且与铜酸盐的实验报告的值一致。

英文摘要:

The three-band \emph{d-p} model is investigated by means of Variational Monte-Carlo (VMC) method with the BCS-like wave-function supplemented by the Gutzwiller and Jastrow correlators. The VMC optimization leads to $d$-$wave$ superconducting state with a characteristic dome-like shape of the order parameter for hole doping $δ\lesssim 0.4$, in a good agreement with the experimental observations. Also, the off-diagonal pair-pair correlation functions, calculated within VMC, vindicates the results obtained very recently within the diagrammatic expansion of the Gutzwiller wave function method (DE-GWF) [cf. Phys. Rev. B \textbf{99}, 104511 (2019)]. Subsequently, the nature of the $d$-$wave$ pairing is investigated by means of recently proposed \emph{minimal-size real-space d-wave pairing operators} [Phys. Rev. B \textbf{100}, 214502 (2019)]. An emergence of the long-range superconducting ordering for both $d$ and $p$ orbitals is reported by analysing the corresponding off-diagonal pair-pair correlation functions. The dominant character of \emph{d-wave} pairing on $d$ orbitals is confirmed. Additionally, the trial wave-function is used to investigate the magnetic properties of the system. The analysis of spin-spin correlation functions is carried out and shows antiferromagnetic $\mathbf{q}=(π,π)$, short-range order, as expected. For the sake of completeness, the charge gap has been estimated, which for the parent compound takes the value $Δ_{CG}\approx1.78\pm0.51\text{ eV}$, and agrees with values reported experimentally for the cuprates.

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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