Anomalous Behaviour of the Phonon Heat Flux in NaCl-NaCl, KBr-KBr and KBr-Cu Point Contacts

Point contacts (PCs) with dimensions smaller than the scattering lengths of charge and heat carriers have been intensively investigated in the recent years. First the conductive PCs with ballistic electric conductivity were studied [1,2]. The observed nonlinearity of the current-voltage characteristics of such contacts which is due to weak inelastic electron scattering is the basis of the method of PC spectroscopy of phonon state density in metals.