Point contact spectroscopy measurements on αt-(BEDT-TTF)2I3

Abstract

We report point-contact spectroscopy 1-V data on superconducting αt-(BEDT-TTF)2I3. The I-V curves show structure in 3 regions: for energies of order 0.25 meV, of about 4,5 meV and for energies of about 10 meV. No structure is observed near the BCS gap (1.3-1.4 meV). We attribute the structure at 4.5 meV to interaction with the phonon possessing this frequency which was observed independently by Raman spectroscopy, and the structure near 0.25 meV to an excitation energy considerably smaller than the BCS gap.