“…The theory developed for the multichannel resonance transport of phonons across the interface between two media (Kosevich Yu. et al, 2008) can be applied to interpret the experimental measurements of the phonon ballistic transport in an Si-Cu point contact (Shkorbatov et al, 1996(Shkorbatov et al, , 1998. These works revealed for the first time the low temperature quantum ballistic transport of phonons in the temperature region 0.1 -3 K. Besides, in some works (Shkorbatov et al, 1996(Shkorbatov et al, , 1998) a reduced point contact heat flux in the regime of the geometric optics was investigated in the temperature interval 3 -10 K. The results obtained in these works showed that in this temperature interval the reduced heat flow through the point contact is a non-monotonous temperature function and has pronounced peaks at temperatures T 1 = 4.46 K, T 2 = 6.53 K and T 3 = 8.77 K. We suppose that the series of peaks for the reduced heat flow (Shkorbatov et al, 1996(Shkorbatov et al, , 1998 could be explained by the models represented in Fig.11 a,b.…”