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arXiv · 2012.14911

Spin-polarized imaging of strongly interacting fermions in the ferrimagnetic state of Weyl candidate CeBi

Christian E. Matt·Yu Liu·Harris Pirie·Nathan C. Drucker·Na Hyun Jo·Brinda Kuthanazhi·Zhao Huang·Christopher Lane·Jian-Xin Zhu·Paul C. Canfield·Jennifer E. Hoffman
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Abstract

CeBi has an intricate magnetic phase diagram whose fully-polarized state has recently been suggested as a Weyl semimetal, though the role of $f$ states in promoting strong interactions has remained elusive. Here we focus on the less-studied, but also time-reversal symmetry-breaking ferrimagnetic phase of CeBi, where our density functional theory (DFT) calculations predict additional Weyl nodes near the Fermi level $E_\mathrm{F}$. We use spin-polarized scanning tunneling microscopy and spectroscopy to image the surface ferrimagnetic order on the itinerant Bi $p$ states, indicating their orbital hybridization with localized Ce $f$ states. We observe suppression of this spin-polarized signature at $E_\mathrm{F}$, coincident with a Fano line shape in the conductance spectra, suggesting the Bi $p$ states partially Kondo screen the $f$ magnetic moments, and this $p-f$ hybridization causes strong Fermi-level band renormalization. The $p$ band flattening is supported by our quasiparticle interference (QPI) measurements, which also show band splitting in agreement with DFT, painting a consistent picture of a strongly interacting magnetic Weyl semimetal.

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Christian E. Matt, Yu Liu, Harris Pirie, Nathan C. Drucker, Na Hyun Jo, Brinda Kuthanazhi, Zhao Huang, Christopher Lane, Jian-Xin Zhu, Paul C. Canfield, Jennifer E. Hoffman. 2020-12-29. Spin-polarized imaging of strongly interacting fermions in the ferrimagnetic state of Weyl candidate CeBi. https://doi.org/10.1103/physrevb.105.085134

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