Ultrafast dynamics in CeCoIn$_{5}$

We present ultrafast pump-probe and transient grating spectroscopy studies of the heavy Fermion superconductor CeCoIn$_{5}$. In pump-probe experiments, a 100-femtosecond 800nm-wavelength pulse creates transient electronic excitations whose decay is probed by studying transient changes in reflectivity as a function of time. We observe changes in pump-probe decay dynamics across the Kondo coherence temperature. In transient grating spectroscopy, two pump-pulses are interfered to produce a spatially periodic excitation, and the system's response to this periodic perturbation is studied through a diffracted probe beam. The temporal evolution of this signal indicates a non-trivial motion of the excitation grating in the heavy electron regime.