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arXiv · 1810.12284

Anisotropic Correlated Electronic Structure of Colossal Thermopower Marcasite FeSb$_2$

A. Chikina·J. -Z. Ma·W. H. Brito·S. Choi·Q. Du·J. Jandke·H. Liu·N. C. Plumb·M. Shi·C. Petrovic·M. Radovic·G. Kotliar
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Abstract

Iron antimonide (FeSb$_2$) is a mysterious material with peculiar colossal thermopower of about $-45$ mV/K at 10 K. However, a unified microscopic description of this phenomenon is far from being achieved. The understanding of the electronic structure in details is crucial in identifying the microscopic mechanism of FeSb$_2$ thermopower. Combining angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations we find that the spectrum of FeSb$_2$ consists of two bands near the Fermi energy: the nondispersive strongly renormalized $\alpha$-band, and the hole-like $\beta$-band that intersects the first one at $\Gamma$ and Y points of the Brillouin zone. Our study reveals the presence of sizable correlations, predominantly among electrons derived from Fe-3d states, and considerable anisotropy in the electronic structure of FeSb$_2$. These key ingredients are of fundamental importance in the description of colossal thermopower in FeSb$_2$.

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A. Chikina, J. -Z. Ma, W. H. Brito, S. Choi, Q. Du, J. Jandke, H. Liu, N. C. Plumb, M. Shi, C. Petrovic, M. Radovic, G. Kotliar. 2018-10-29. Anisotropic Correlated Electronic Structure of Colossal Thermopower Marcasite FeSb$_2$. https://doi.org/10.1103/physrevresearch.2.023190

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