Electronic structure and quantum criticality in Ba(Fe$_{1-x-y}$Co$_{x}$Mn$_{y}$)$_{2}$As$_{2}$, an ARPES study

TL;DR

This study uses ARPES and DFT calculations to investigate the electronic structure of Ba(Fe,Co,Mn)2As2, revealing that Mn substitution localizes holes and does not support quantum criticality at optimal doping.

Contribution

It provides new insights into the effects of Mn doping on the electronic structure and challenges previous quantum criticality models in this material.

Findings

Mn does not cause hole doping, indicating hole localization.

No diverging effective mass or scattering rate near optimal doping.

Results suggest a continuous evolution of quasiparticle interactions.

Abstract

We used angle-resolved photoemission spectroscopy (ARPES) and density functional theory calculations to study the electronic structure of Ba(Fe1-x-yCoxMny)2As2 for x=0.06 and 0<=y <=0.07. From ARPES we derive that the substitution of Fe by Mn does not lead to hole doping, indicating a localization of the induced holes. An evaluation of the measured spectral function does not indicate a diverging effective mass or scattering rate near optimal doping. Thus the present ARPES results indicate a continuous evolution of the quasiparticle interaction and therefore question previous quantum critical scenarios.