Extremely Large Magnetoresistance in Bi$_{\mathrm{0.96}}$Sb$_{\mathrm{0.04}}$*

Recent experimental evidence for Weyl fermions in topological semimetals has attracted considerable attention. These materials are three-dimensional analogue of graphene. The present work is motivated by the recent prediction of Weyl semi-metallic phase in Bi$_{\mathrm{1-x}}$Sb$_{\mathrm{x}}$ alloys. In this paper we present the electronic transport properties studied under high applied magnetic fields in Bi$_{\mathrm{0.96}}$Sb$_{\mathrm{0.04}}$ alloys. The sample exhibits extremely high magneto-resistance; MR(5 K, 8 T) $=$ 9.8\texttimes 10$^{\mathrm{4}}$ {\%}. This value is comparable to the MR observed in recently discovered other members of these emergent materials. Most importantly, this composition shows large MR at room temperature, MR (300 K, 8 T) $=$ 435{\%}, which is almost twice to that observed in Dirac semimetal Cd$_{\mathrm{3}}$As$_{\mathrm{2}}$ ($=$ 200 {\%} at 14.5 T) and Weyl semimetal NbP ($=$ 250{\%} at 9 T). We also discuss single crystal growth techniques as well as Hall and Shubnikov de Haas (SdH) oscillation data. \textbf{References } [1] S. Singh et.al, \textit{arxiv:1512.00863v2} (2015). [2] C. Shekhar et.al, \textit{Nat. Phys.}\textbf{11} 645--650 (2015). [3] Z. Wang et.al, \textit{Phys. Rev. B} \textbf{88 }125427 (2013).