Isotope effect and the role of phonons in the iron-based superconductors

被引：14

作者：

Bang, Yunkyu ^{[1
,2
]}

机构：

[1] Chonnam Natl Univ, Dept Phys, Kwangju 500757, South Korea

[2] Asia Pacific Ctr Theoret Phys, Pohang 790784, South Korea

来源：

PHYSICAL REVIEW B | 2009年 / 79卷 / 09期

关键词：

antiferromagnetism; barium compounds; cerium compounds; electronic density of states; iron compounds; isotope effects; lanthanum compounds; neodymium compounds; phonons; potassium compounds; strontium compounds; superconducting materials; superconducting transition temperature; LAYERED SUPERCONDUCTOR; GAPS;

D O I：

10.1103/PhysRevB.79.092503

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We studied the isotope effect of phonon in the Fe-based superconductors using a phenomenological two band model for the sign-changing s-wave (+/- s-wave) state. Within this mean-field model, we showed that the large isotope effect is not inconsistent with the +/- s-wave pairing state and its high transition temperature. In principle, a large phonon isotope coefficient alpha implies a large phonon coupling constant. However, the asymmetric density of states between two bands substantially enhances the value of alpha, so that a moderate value of the phonon coupling constant (lambda(ph)approximate to 0.4) can produce a very large value of alpha(approximate to 0.4) as well as a high transition temperature together with an antiferromagnet-induced interaction.

引用

页数：4

共 34 条

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