Exploring the Dirac nature of RbBi2

Characteristics of topological semimetals such as a nonsaturating magnetoresistance (MR), a field-induced metal to semiconducting crossover and a robust resistivity plateau are observed under a magnetic field in type-I RbBi₂ bulk superconductor with $\\mathrm{T}$_c = 4.15 K. The MR exhibits a notable 3500% increase at 2 K and 9 T and the resistivity follows a power law temperature dependence, while the MR ∝ $\\mathrm{H}$^1.26, indicating weak carrier compensation. Further, first principles calculations provided insights into the dynamical stability of the cubic structure at 0 K. Both hole and electron pockets are observed at the Fermi surface. The electron-phonon interaction constant indicates weak coupling strength (<1) that leads to a maximum predicted $\\mathrm{T}$_c of 2.852 K. Just below the Fermi level, E_F, the electronic band structure consists of linear band crossings at the $\\mathrm{X}$ points in the Brillouin zone (BZ) corresponding to massless, symmetry-protected Dirac fermions.