Electronic structure evolution of the magnetic Weyl semimetal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Co</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mi>Sn</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">S</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> with hole and electron doping
Himanshu Lohani, Paul Foulquier, Patrick Le Fèvre, François Bertran, D. Colson, A. Forget, V. Brouet
Abstract
${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ has been established as a prototype of a magnetic Weyl semimetal, exhibiting a giant anomalous Hall effect in its ferromagnetic phase. An attractive feature of this material is that Weyl points lie close to the Fermi level, so one can expect a high reactivity of the topological properties to hole or electron doping. We present here a direct observation with angle-resolved photoemission spectroscopy of the evolution of the electronic structure under different types of substitutions: In for Sn (hole doping outside the kagome Co plane), Fe for Co (hole doping inside the kagome Co plane), and Ni for Co (electron doping inside the kagome Co plane). We observe clear shifts of selected bands, which are due both to doping and to the reduction of the magnetic splitting by doping. We discriminate between the two by studying the temperature evolution from a ferromagnetic to paramagnetic state. We discuss these shifts with the help of density-functional theory calculations using the virtual crystal approximation. We find that these calculations reproduce rather well the evolution with In, but largely fail to capture the effect of Fe and Ni, where local behavior at the impurity site plays an important role.