The recently discovered large nonsaturating magnetoresistance in semimetal $\mathrm{WT}{\mathrm{e}}_2$ may result from near-perfect electron-hole compensation, however recent reports question whether the compensation is adequate to explain the observations. Experiments on significantly uncompensated $\mathrm{WT}{\mathrm{e}}_2$ are needed. We measure magnetoresistance ${\rho }_{xx}\left(H\right)$, Hall effect ${\rho }_{xy}\left(H\right)$, and an electrolyte gating effect in thin (<100 nm) exfoliated $\mathrm{WT}{\mathrm{e}}_2$. We observe ${\rho }_{xy}\left(H\right)$ linear in $H$ at low $H$ consistent with near-perfect compensation, however ${\rho }_{xy}\left(H\right)$ becomes nonlinear and changes sign with increasing $H$, implying a breakdown of compensation. We break compensation more significantly by using an electrolytic gate for highly electron-doped $\mathrm{WT}{\mathrm{e}}_2$ with Li. In gated $\mathrm{WT}{\mathrm{e}}_2$ the nonsaturating ${\rho }_{xx}\left(H\right)$ persists to $H=14\mathrm{T}$, even with significant deviation from perfect electron-hole compensation $(p/n=0.84)$ where the two-band model predicts a saturating ${\rho }_{xx}\left(H\right)$. Our results indicate electron-hole compensation is not the mechanism for extremely large magnetoresistance in $\mathrm{WT}{\mathrm{e}}_2$; alternative explanations are needed.

• Received 6 October 2015
• Revised 7 March 2016

DOI:https://doi.org/10.1103/PhysRevB.93.121108