Possible Direct Observation of Phasons in Potassium

Abstract

The nonlinear response expected in a potassium point-contact device has been calculated with inclusion of the electron-phason interaction of Overhauser. With use of the theory of Kulik et al., to describe the point contact, a peak is found at low energy (at approximately 0.3 meV). This peak agrees well in energy, shape, and magnitude with an unexplained peak in the point-contact data of Jansen et al. A rather strong temperature dependence of the position, shape, and magnitude of this peak has also been found in the present calculations.