Enhanced Fermi surface nesting in superconducting BaFe$_2$(As$_{1-x}$P$_x$)$_2$ revealed by de Haas-van Alphen effect

TL;DR

This study uses the de Haas-van Alphen effect to reveal enhanced three-dimensional Fermi surface nesting in superconducting BaFe$_2$(As$_{1-x}$P$_x$)$_2$, highlighting its potential role in superconductivity.

Contribution

It provides the first detailed three-dimensional Fermi surface mapping of superconducting BaFe$_2$(As$_{1-x}$P$_x$)$_2$ using dHvA, showing improved nesting compared to non-superconducting phosphides.

Findings

Fermi surfaces are well nested in the (,) direction.

Inner electron and hole pockets have similar areas and warping.

Nesting correlates with the superconducting state.

Abstract

The three-dimensional Fermi surface morphology of superconducting BaFe_2(As_0.37}P_0.63)_2 with T_c=9K, is determined using the de Haas-van Alphen effect (dHvA). The inner electron pocket has a similar area and k_z interplane warping to the observed hole pocket, revealing that the Fermi surfaces are geometrically well nested in the (\pi,\pi) direction. These results are in stark contrast to the Fermiology of the non-superconducting phosphides (x=1), and therefore suggests an important role for nesting in pnictide superconductivity.