Enhancement of Heat Pulses in Crystals due to Elastic Anisotropy

摘要: The generation of thermal acoustic waves by a heated metallic film on the surface dielectric crystal at low temperatures is discussed. It shown that even if produced correspond to uniform distribution directions wave vector, there may be large enhancement energy flow in some crystallographic compared average. This effect arises because elastic anisotropy. Explicit expressions are given for expected principal cubic crystals.