Generalized BCS Equations and the Iron-Pnictide Superconductors

Gulshan P. Malik, Israel Chávez, Manuel de Llano

Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, México DF, México.
Theory Group, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.

DOI: 10.4236/jmp.2013.44067                

Abstract

A detailed quantitative study of the pnictide composite superconductor (CS) Ba_0.6K_0.4Fe₂As₂ is presented in the frame-work of the recently derived set of generalized BCS equations. Invoking multiple Debye temperatures to take into account anisotropy of the CS, we address the current experimental data on its T_c and the (not so clear-cut) gap-values via different theoretical scenarios that attempt to identify the ion species responsible for pairing in it. This is done with the aid of the Bogoliubov’s restriction on the BCS dimensionless electron-phonon coupling constant. Significantly, our study sheds light on the gaps which have recently been observed in different iron-pnictide CSs as nodes or line-nodes on the Fermi surface and have evinced considerable interest.

Keywords

Generalized BCS Equation; Iron-Pnictide Superconductors; Multiple Gaps

Conflicts of Interest

The authors declare no conflicts of interest.

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