Linear magnetoresistance induced by mobility fluctuations in iodine-intercalated tungsten ditelluride

Abstract

We report a systematic study of the magnetoresistance, Hall effect, and the electronic structure in an iodine-intercalated tungsten ditelluride (${\mathrm{WTe}}_{2}\mathrm{I}$) single crystal, which crystallizes in a centrosymmetric structure. ${\mathrm{WTe}}_{2}\mathrm{I}$ presents significant anisotropic magnetotransport behavior with the magnetic field rotated in the $xz$ and $yz$ planes and violation of the Kohler's rule. Unexpectedly, nonsaturating linear magnetoresistance (LMR) was observed under the magnetic field parallel to the $z$ axis and the current along the $x$ axis. The analysis of the Hall effect reveals that the carrier mobility in ${\mathrm{WTe}}_{2}\mathrm{I}$ is notably lower than that of ${\mathrm{WTe}}_{2}$ and meets the picture of the Parrish and Littlewood model, suggesting that the LMR is likely caused by disorder effects. First-principles calculations show that the electronic structure undergoes a topological phase transition from a Weyl state to a Dirac state due to iodine intercalation. This finding provides a platform to search for physical phenomena related to ${\mathrm{WTe}}_{2}$ and study the topological phase transition.