Effect of phonon confinement on heat dissipation in ridges

We have investigated experimentally the effect of lateral confinement of acoustic phonons in ridges as a function of the temperature. Electrical methods are used to generate phonons in 100nm large nanostructures and to probe the nanostructure temperature in the same time, what allows tracking the heat flux generated and its possible deviation from Fourier diffusive heat conduction. We compare our results with those of a recent theoretical paper based on the ballistic-diffusive equations.