Phase diagram and superconducting states in LaFeAsO1-xHx based on the multiorbital extended Hubbard model
Phase diagram and superconducting states in LaFeAsO1-xHx based on the multiorbital extended Hubbard model
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DOI：
10.1103/physrevb.88.041106
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发表时间：
2013-07-22
影响因子：
3.7
通讯作者：
Hosono, H.
中科院分区：
文献类型：
--
作者：
Yamakawa, Y.;Onari, S.;Hosono, H.
为了理解最近建立的独特的 LaFeAsO1-xHx 磁性和超导相图，我们分析了超出刚性带近似的 x = 0-0.4 的实际多轨道紧束缚模型。自旋和轨道磁化率都是在库仑和电荷四极相互作用存在的情况下计算的。研究发现，由于 LaFeAsO1-xHx 中刚性带图的强烈违反，在类似于 0 和 0.4 的 x 处，轨道和自旋涨落都强烈发展。基于这一结果，我们讨论了实验相图，特别是双穹顶超导相。此外，我们表明，库仑相互作用引起的顶点校正有效地产生了四极相互作用，导致自旋和轨道涨落的相互发展。
To understand the recently established unique magnetic and superconducting phase diagram of LaFeAsO1-xHx, we analyze the realistic multiorbital tight-binding model for x = 0-0.4 beyond the rigid-band approximation. Both the spin and orbital susceptibilities are calculated in the presence of the Coulomb and charge quadrupole interactions. It is found that both orbital and spin fluctuations strongly develop at both x similar to 0 and 0.4, due to the strong violation of the rigid-band picture in LaFeAsO1-xHx. Based on this result, we discuss the experimental phase diagram, especially the double-dome superconducting phase. Moreover, we show that the quadrupole interaction is effectively produced by the vertex correction due to Coulomb interaction, resulting in the mutual development of spin and orbital fluctuations.