Distinct topological properties in Ce monopnictides having correlated f electrons: CeN vs. CeBi

Dong-Choon Ryu,J D Denlinger,Chang-Jong Kang,B I Min,Junwon Kim,Kyoo Kim

doi:10.1103/physrevresearch.2.012069

Dong-Choon Ryu, J D Denlinger + Show 4 more

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https://doi.org/10.1103/physrevresearch.2.012069

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Abstract

This paper finds that f-electrons play a crucial role in the nontrivial Z2 topology. They demonstrate the coherent quasi-particle band formation of f-electrons in CeN even at room temperature, which brings about the topological Kondo nature originating from the f-d band inversion. The distinct topological properties in CeN and CeBi, Dirac cones and helical spin textures at their respective surfaces, provide evidence of the dual-nature of f-electrons.

Highlights

The hitherto-studied topological nature in Ce monopnictides (CePn) has been discussed based solely on their p-d band inversion, despite the existence of f electrons
Based on bulk-sensitive soft x-ray angle-resolved photoemission spectroscopy (ARPES) and density-functional theory (DFT) calculations, Oinuma et al [2] reported that CeSb is merely a topologically trivial semimetal without p-d band inversion, and that the Dirac-cone-like states observed in VUV ARPES are not of a topological origin
The double Dirac cones anticipated to be at Min Fig. 1(a), which are induced from band inversions at two nonequivalent bulk X points, would be gapped by their mutual hybridization, so as to lose their topological signature revealing trivial Rashba-type surface states [4,5]

Summary

Rapid Communications

Distinct topological properties in Ce monopnictides having correlated f electrons: CeN vs. CeBi. Based on bulk-sensitive soft x-ray ARPES and density-functional theory (DFT) calculations, Oinuma et al [2] reported that CeSb is merely a topologically trivial semimetal without p-d band inversion, and that the Dirac-cone-like states observed in VUV ARPES are not of a topological origin. Note that the topological nature for CePn has been investigated based solely on p-d band inversion because f electrons in CeSb and CeBi are assumed to be inactive due to their localized nature [1,2,3,4] This assumption, is no longer valid when the Ce-Ce distances become closer, as in CeN [see Fig. 1(b)]. This suggests that the TSSs would possibly emerge in CeN through f -d band inversion, quite distinctly from

Published by the American Physical Society

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