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Title: Tuning of anomalous magnetotransport properties in half-Heusler topological semimetal GdPtBi

Authors: Orest Pavlosiuk, Piotr Wiśniewski, Romain Grasset, Marcin Konczykowski, Andrzej Ptok, Dariusz Kaczorowski

Journal: Materials Horizons

DOI: 10.1039/d4mh01875c   

Although theoretical predictions indicate the existence of tens of thousands of topological materials (materials whose electronic structure has a non-trivial topology) among inorganic compounds, in practice only a few of them show signatures of these states in their magnetotransport properties. One possible reason for this discrepancy is that topologically non-trivial states often located far from the Fermi level, and thus do not directly affect the transport properties of the material. The compound GdPtBi, which belongs to the half-Heusler family, is the first known Weyl semimetal in which the Weyl nodes are induced by external magnetic field, and one of the few materials in which the effect of non-trivial topology of electronic structure on magnetotransport properties is observed.

In a recent article published in the Materials Horizons, researchers from the Magnetic Research Division, together with partners from École Polytechnique (Palaiseau, France) and the Institute of Nuclear Physics of the Polish Academy of Sciences, have shown that the Fermi level in the topological semimetal GdPtBi can be tuned by high-energy electron irradiation. Significantly, despite a shift of the Fermi level by more than 100 meV from its initial position, the material still exhibits the characteristic features of topologically non-trivial electronic states, in particular a negative longitudinal magnetoresistance. In addition, it was found that the magnitude of the anomalous Hall effect depends in a complex way on the irradiation dose. The obtained results, also confirmed by theoretical calculations, allow a better understanding of the relationship between the electronic structure and the magnetotransport properties of this type of materials.

The results open new possibilities for fine-tuning the properties of topological materials, and similar effects are likely to be observed in other topological semimetals with small Fermi surfaces.

This research was financially supported by the National Science Centre of Poland, project SHENG, grant no. 2021/40/Q/ST5/00066