Topological Kondo semimetals in hexagonal crystal systems

Topological semimetals are materials whose electronic structures host band degeneracies with non-trivial topology. Realizing topological semimetals in strongly-correlated settings will both advance the classification of interacting gapless electronic topology and serve as an anchoring point to study the broad landscape of correlated topological phases. In the Weyl-Kondo semimetals [1,2], the low-energy heavy-fermion excitations from the Kondo effect exhibit band degeneracies, such as Weyl points and Weyl nodal lines, stabilized by topology or crystalline symmetries. Going beyond the cubic [1,2] and square-net [3,4] crystal structures, hexagonal crystal structures represent an important platform for electronic topology. In this work, we perform calculations to identify topological Kondo semimetals in hexagonal crystal systems and advance their material realizations. Potential experimental signatures, and the broad implication to the field of quantum materials will also be discussed.

Supported by the Carl and Lillian Illig Postdoctoral Fellowship from the Smalley-Curl Institute at Rice University (K.-S. L.), the AFOSR (FA9550-21-1-0356), NSF (DMR-2220603) and VBFF (N00014-23-1-2870).

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[2] S. Dzsaber et al., Phys. Rev. Lett. 118, 246601 (2017); PNAS 118, e2013386118 (2021).

[3] L. Chen et al., Nat. Phys. 18, 1341 (2022).

[4] Y. Fang et al., arXiv:2403.02295 (2024).