Magnetotransport in Sr3PbO antiperovskite with three-dimensional massive Dirac electrons

Abstract

Novel topological phenomena are anticipated for three-dimensional (3D) Dirac electrons. The magnetotransport properties of cubic $\mathrm{S}{\mathrm{r}}_3\mathrm{PbO}$ antiperovskite, theoretically proposed to be a 3D massive Dirac electron system, are studied. The measurements of Shubnikov-de Haas oscillations and Hall resistivity indicate the presence of a low density ($\sim 1\times 10^{18}$ $\mathrm{c}{\mathrm{m}}^{-3}$) of holes with an extremely small cyclotron mass of 0.01-0.06$m_e$. The magnetoresistance $\Delta {\rho }_{xx}(B)$ is linear in magnetic field $B$ with the magnitude independent of temperature. These results are fully consistent with the presence of 3D massive Dirac electrons in $\mathrm{S}{\mathrm{r}}_3\mathrm{PbO}$. The chemical flexibility of the antiperovskites and our findings in the family member, $\mathrm{S}{\mathrm{r}}_3\mathrm{PbO}$, point to their potential as a model system in which to explore exotic topological phases.