Fermi surface and mass enhancement in KFe$_2$As$_2$ from de Haas-van Alphen effect measurements

TL;DR

This study combines band structure calculations and de Haas-van Alphen measurements to investigate the Fermi surface and effective mass enhancements in KFe$_2$As$_2$, revealing significant electronic correlations in this iron pnictide superconductor.

Contribution

It provides the first detailed experimental and theoretical analysis of the Fermi surface and mass enhancement in KFe$_2$As$_2$, highlighting the role of electronic correlations.

Findings

Three cylindrical Fermi surfaces identified

Effective electron masses range from 6 to 18 times free electron mass

Large mass enhancement ($ 3$) indicates strong electronic correlations

Abstract

We report on a band structure calculation and de Haas-van Alphen measurements of KFe$_2$As$_2$. Three cylindrical Fermi surfaces are found. Effective masses of electrons range from 6 to 18$m_e$, $m_e$ being the free electron mass. Remarkable discrepancies between the calculated and observed Fermi surface areas and the large mass enhancement ($\gtrsim 3$) highlight the importance of electronic correlations in determining the electronic structures of iron pnicitide superconductors.