| Autor: |
McNally, D. E., Zellman, S., Yin, Z. P., Post, K. W., He, Hua, Hao, K., Kotliar, G., Basov, D., Homes, C. C., Aronson, M. C. |
| Rok vydání: |
2015 |
| Předmět: |
|
| Zdroj: |
Physical Review B 92, 115142 (2015) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.92.115142 |
| Popis: |
We present optical transmission measurements that reveal a charge gap of 0.86 eV in the local moment antiferromagnetic insulator BaMn$_2$As$_2$, an order of magnitude larger than previously reported. Density functional theory plus dynamical mean field theory (DFT+DMFT) calculations correctly reproduce this charge gap only when a strong Hund's coupling is considered. Thus, BaMn$_2$As$_2$ is a member of a wider class of Mn pnictide compounds that are Mott-Hund's insulators. We also present optical reflectance for metallic 2% K doped BaMn$_2$As$_2$ that we use to extract the optical conductivity at different temperatures. The optical conductivity $\sigma_1$($\omega$) exhibits a metallic response that is well described by a simple Drude term. Both $\sigma$($\omega$$\rightarrow$0, T) and $\rho$(T) exhibit Fermi liquid temperature dependencies. From these measurements, we argue that a more strongly correlated Hund's metal version of the parent compounds of the iron pnictide superconductors has not yet been realized by doping this class of Hund's insulators. |
| Databáze: |
arXiv |
| Externí odkaz: |
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