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arXiv · 1807.05388

Electronic structure of metallic tetra-boride $\textrm{TmB}_{\textrm{4}}$: An LDA+DMFT study

Nandan Pakhira·Jyoti Krishna·S. Nandy·T. Maitra·A Taraphder
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Abstract

Recent experimental observations of magnetization plateau in metallic tetraboride $\textrm{TmB}_{4}$ have created a lot of interest in these class of materials. Hysteretic longitudinal resistance and anomalous Hall Effect are other remarkable features in the rare-earth tetraborides which represent experimental realizations of Archimedean Shastry-Sutherland (SSL) lattice. Electronic band structures, calculated under GGA and GGA+SO approximations, show that $\textrm{TmB}_{4}$ is a narrow band system with considerable correlation in its f-level. Strong correlation effects in this system are studied under single-site dynamical mean field theory (DMFT) [LDA+DMFT scheme] using multi-orbital generalization of iterated perturbation theory (MO-IPT). Pseudo-gap behaviour in spectral function and non-Fermi liquid behaviour of self-energy shows non-trivial strong correlation effects present in this geometrically frustrated metallic magnets. We also consider the extant, heather-to-neglected, strong atomic spin-orbit coupling (SOC) effects. While there is a significant change in the topology of the Fermi surface in the presence of SOC, the non-Fermi liquid behavior survives. The system can be modelled by an effective two orbital spinless Falicov-Kimball model together with two free band like states.

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Nandan Pakhira, Jyoti Krishna, S. Nandy, T. Maitra, A Taraphder. 2018-07-14. Electronic structure of metallic tetra-boride $\textrm{TmB}_{\textrm{4}}$: An LDA+DMFT study. https://arxiv.org/abs/1807.05388

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