Temperature dependence of point-contact spectroscopy in copper

Abstract

The current-voltage characteristics of Cu point contacts have been studied experimentally between 5 and 300 K. The effect of the temperature on the measured $\frac{d^{2}V}{d{I}^2}$ curves is a broadening of the spectrum for the electron-phonon interaction in the metal. The measured resistance of a point contact is compared with the resistivity of bulk material as a function of the temperature. An analysis of the broadening of the spectra and the temperature dependence of the contact resistance is given. Differences between the temperature dependences of the resistance of a point contact and that of the bulk are ascribed to different transport efficiencies for the electron-phonon interaction in these two cases.