Tuning the electrical transport of type II Weyl semimetal WTe₂ nanodevices by Ga+ ion implantation

Here we introduce lattice defects in WTe₂ by Ga+ implantation (GI), and study the effects of defects on the transport properties and electronic structures of the samples. Theoretical calculation shows that Te Frenkel defects is the dominant defect type, and Raman characterization results agree with this. Electrical transport measurements show that, after GI, significant changes are observed in magnetoresistance and Hall resistance. The classical two-band model analysis shows that both electron and hole concentration are significantly reduced. According to the calculated results, ion implantation leads to significant changes in the band structure and the Fermi surface of the WTe₂. Our results indicate that defect engineering is an effective route of controlling the electronic properties of WTe₂ devices.