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arXiv · 1202.1607

Pairing Symmetry and Spin Excitations of Iron Selenide Superconductors

Tao Zhou·Z. D. Wang
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Abstract

We propose an effective single-band model for the newly discovered iron selenide superconductors A$_x$Fe$_{2-y}$Se$_2$ (A=Tl,K,Rb,Cs). Based on this minimum model and the random phase approximation, the $d_{x^2-y^2}$ pairing symmetry is revealed theoretically, which may be understood in the framework of Fermi surface topology. A common origin of superconductivity is elucidated for this compound and other high-T$_c$ materials. The spin excitations at $(\pi,\pi/2)$ in superconducting states are observed, in good agreement with the neutron scattering experiments. The spin resonance is indicated to show up only for the d-wave pairing, which provides an additional indication for the d-wave pairing symmetry in this family of superconductors.

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Tao Zhou, Z. D. Wang. 2012-02-08. Pairing Symmetry and Spin Excitations of Iron Selenide Superconductors. https://arxiv.org/abs/1202.1607

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