Fermi-surface topology of the iron pnictide LaFe$_2$P$_2$

TL;DR

This study combines experimental de Haas--van Alphen measurements with density-functional calculations to analyze the Fermi-surface topology of LaFe$_2$P$_2$, revealing the absence of a key hole-like Fermi surface and its implications for superconductivity.

Contribution

It provides the first detailed Fermi-surface topology of LaFe$_2$P$_2$ and links the absence of superconductivity to the missing nesting condition.

Findings

Only one quasi-two-dimensional Fermi-surface sheet observed

No hole-like Fermi surface around $\Gamma$

LaFe$_2$P$_2$ exhibits no superconductivity despite mass enhancements

Abstract

We report on a comprehensive de Haas--van Alphen (dHvA) study of the iron pnictide LaFe$_2$P$_2$. Our extensive density-functional band-structure calculations can well explain the measured angular-dependent dHvA frequencies. As salient feature, we observe only one quasi-two-dimensional Fermi-surface sheet, i.e., a hole-like Fermi-surface cylinder around $\Gamma$, essential for $s_\pm$ pairing, is missing. In spite of considerable mass enhancements due to many-body effects, LaFe$_2$P$_2$ shows no superconductivity. This is likely caused by the absence of any nesting between electron and hole bands.