Electron and hole Dirac cone states in-pairs in Ba(FeAs)$_2$ confirmed by magnetoresistance

TL;DR

This study confirms the presence of paired electron and hole Dirac cone states in Ba(FeAs)$_2$, revealing their high mobility and significance in the material's low-temperature electronic behavior through magnetoresistance measurements.

Contribution

It demonstrates that both electron and hole Dirac cone states coexist as high mobility carriers in Ba(FeAs)$_2$, challenging previous assumptions and providing a new understanding of its quantum transport properties.

Findings

Linearly increasing magnetoresistance at low temperatures.

Both electron and hole states are high mobility Dirac cones.

Paired electron-hole Dirac states are essential for understanding electronic behavior.

Abstract

The quantum transport of Dirac cone states in the iron pnictide Ba(FeAs)$_2$ with a d-\,multiband system is studied by using single crystal samples. The transverse magnetoresistance develops linearly against magnetic field at low temperatures. The transport phenomena are interpreted in terms of the 0$^{th}$ Landau level by applying the theory predicted by Abrikosov. The results of the semiclassical analyses of a two carrier system under low magnetic field limit show that both electron and hole reside as the high mobility states, being indicative to the fact that both electron- and hole Dirac cone states should be taken into account in pairs for having the real interpretation of low temperature electronic states in iron pnictides, being in contrast to the previous reports.