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arXiv · 2311.11488

Observation of multiple flat bands and van Hove singularities in the distorted kagome metal NdTi3Bi4

Mazharul Islam Mondal·Anup Pradhan Sakhya·Milo Sprague·Brenden R. Ortiz·Matthew Matzelle·Arun K Kumay·Avike Seal·Barun Ghosh·Arun Bansil·Madhab Neupane
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Abstract

Kagome materials have attracted enormous research interest recently owing to their diverse topological phases and manifestation of electronic correlation. Here, we present the electronic structure of a distorted ferromagnetic kagome metal, NdTi3Bi4, exhibiting a transition temperature of 9 K. Our investigation employs a combination of angle-resolved photoemission spectroscopy (ARPES) measurements and density functional theory (DFT) calculations. We discover the presence of two flat bands which are found to originate from the kagome structure formed by Ti atoms with major contribution from Ti dxy and Ti dx2-y2 orbitals. We also observed multiple van Hove singularities (VHSs) in its electronic structure, with one VHS lying near the Fermi level. The ARPES data reveals the existence of Dirac cone at the K point, a finding which is corroborated by our DFT calculations. These findings present detailed electronic structure capable of hosting correlation-driven phenomenon in this novel ferromagnetic kagome metal.

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Mazharul Islam Mondal, Anup Pradhan Sakhya, Milo Sprague, Brenden R. Ortiz, Matthew Matzelle, Arun K Kumay, Avike Seal, Barun Ghosh, Arun Bansil, Madhab Neupane. 2023-11-20. Observation of multiple flat bands and van Hove singularities in the distorted kagome metal NdTi3Bi4. https://doi.org/10.1103/mhj5-ws5v

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