Abstract
We report an experimental and theoretical investigation of the electron-boson interaction in by point-contact (PC) spectroscopy, model, and ab initio local density approximation–based calculations for the standard electron-phonon Eliashberg function. The PC spectrum viz. the second derivative of the characteristic of representative PC exhibits a pronounced maximum at about 20 meV and surprisingly a featureless behavior at lower and higher energies. We discuss phonon and nonphonon (excitonic) mechanisms for the origin of this peak. Analysis of the underlying source of this peak may be important for the understanding of serious puzzles of superconductivity in this type of compound.
- Received 23 May 2014
- Revised 5 August 2014
DOI:https://doi.org/10.1103/PhysRevB.90.094505
©2014 American Physical Society