Ultrafast dynamics in Weyl semimetal (W,Mo)Te_2

(W,Mo)Te_2 is reported to be a type-II Weyl semimetal, and this classification depends on its structural phase and details of its electronic band structure on the unoccupied side. Tuning of the W/Mo ratio can alter the structural phase transition temperature, spin-orbit coupling strength, and interlayer interactions, the latter two which affect the electronic structure. Optical pump-probe reflectivity experiments are sensitive to both crystal structure and electronic structure via coherent phonon oscillations and decay dynamics, respectively. Here we show the temperature and composition evolution of structural and electronic dynamics in (W,Mo)Te_2.