Erratum:  Picosecond acoustic phonon pulse generation in nickel and chromium [Phys. Rev. B 67, 205421 (2003)]

Figure 2

(Color online) (a) First echoes for relative amplitude $\rho$ and phase $\delta \varphi$ for a $200\mathrm{nm}$ film of polycrystalline Ni on silicon (100), plotted on identical scales. (b) First echoes for a $190\mathrm{nm}$ film of Cr on silicon (100). The background thermal decay has been subtracted from all four experimental traces (thin solid curves). The thick solid curves are the results of calculations including both thermal and electron diffusion. The dashed-dotted curves correspond to a theoretical fit including only thermal diffusion $(g\to \infty )$, and the dashed curves to a theoretical fit in the absence of diffusion $(g\to \infty ,\kappa \to 0)$. The theoretical curves include the effect of ultrasonic attenuation, only significant for Cr.