Phonon transport in pressure-made point contacts

Abstract

A theoretical and experimental analysis of the heat conductivity in metal-dielectric point contacts is given. The contribution of the phonon diffraction effects to the heat conductivity is investigated. The phonon heat transport through the point contacts is measured from 0.1 K to 100 K using the anvil-needle technique. In KBr-KBr and KBr-Cu point contacts, substituting a Cu needle for the dielectric cold edge does not disturb the heat conductivity pattern. Measurements for Si-Cu point contacts reveal well-defined diffraction maxima of reduced heat conductivity at temperatures in the range 0.5 K-1 K.

Resonance absorption, reflection, transmission of phonons and heat transfer through interface between two solids

“…where A The above theory can be developed for the multichannel resonance transport of phonons across the interface between two media and can be applied for the interpretation of experimental measurements of the phonon ballistic transport in the point contacts Si-Cu [11,12]. These works have revealed for the first time the low-temperature quantum ballistic transport of phonons in the temperature region from 0.1 to 3 K. Besides that, in papers [11,12] a reduced point contact heat flow in the regime of the geometric optics for phonons was measured in the temperature interval from 3 to 10 K. The results obtained in these experiments have shown that in this temperature interval the reduced heat flow through the point contact is a nonmonotonous function of temperature and has pronounced peaks at temperatures T 1 = 4.46 K, T 2 = 6.53 K, T 3 = 8.77 K. We suppose that the series of the peaks of the reduced heat flow could be explained [11,12] by the model presented in Fig.…”

Effect of intermediate layer on resonance phonon transport

“…An anomalously large peak of the reduced heat flow was observed in this temperature interval. This peak was predicted theoretically in the work [3] in which the theory of the quantum transport of phonons in point contacts was presented. Experimental works [1,2] also revealed a series of additional peaks in the temperature dependence of the reduced heat flow at temperatures exceeding 4 K. In this temperature region the phonon transport is realized in the geometric optics regime, as follows from the theory of the quantum point-contact transport of phonons [3,4].…”

“…The heat flow in the ballistic regime of Si-Cu point contacts in the temperature range from 0.1 to 10 K was studied experimentally in [1,2]. An anomalously large peak of the reduced heat flow was observed in this temperature interval.…”

The Features of Low Frequency Atomic Vibrations and Propagation of Acoustic Waves in Heterogeneous Systems

“…Using the results presented in Fig. 11d we can interpret experimental results (Shkorbatov et al, 1996(Shkorbatov et al, , 1998 presented in Fig. 11c.…”

“…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.…”