Wang et al. Reply:

Figure 1

The transient electronic temperatures in ${\mathrm{Bi}}_2{\mathrm{Se}}_3$ measured at 70 K (adapted from Ref. [4]). The black arrow indicates the temperature $\sim 106\mathrm{K}$ for the ${A_{1g}}^1$ phonon ($\hslash {\mathit{\omega }}_p\sim 2.2\mathrm{THz}\approx 9.1\mathrm{meV}$).