Anisotropy of electron-phonon interaction spectra in a magnetic field and quantum interference effects in antimony point contacts

Peculiarities of point-contact spectra behavior of antimony are investigated in a magnetic field. It turns out that the singularities in the spectra can both decrease and increase depending not only on orientation of the contact axes with respect to the crystallographic axis of Sb and the magnetic field vector, but also on the ratio between the contact diameter, the Larmour radius of the charge carriers and their mean free path. The spectrum sign inversion for a dirty contact that is due to electron state delocalization as a result of electronphonon interaction is detected. It means that point-contact spectroscopy is possible in highly disordered materials when the quantum localization is significant.