Evidence of strong electron-phonon interaction in superconducting MgB$_2$ from electron tunneling

A. I. D'yachenko; V. Yu. Tarenkov; A. V. Abal'oshev; S. J. Lewandowski

paper

Evidence of strong electron-phonon interaction in superconducting MgB $_{2}$ from electron tunneling

arXiv:cond-mat/0201200

Abstract

We report tunneling measurements of the electron-phonon (e-ph) interaction in superconducting MgB $_{2}$ using the MgB $_{2}$ -I-Nb junctions, where I stands for insulator. The phonon structure in tunneling density of states in MgB $_{2}$ clearly indicates strong e-ph coupling for the E $_{2 g}$ in-plane boron phonons in a narrow range around 60 meV. The Eliashberg spectral function $α^{2} (ω) F (ω)$ reconstructed from the tunneling data, exhibits significant additional contribution into e-ph interaction from other vibrations such as acoustic ( $\sim 38$ meV) and optical ( $\sim 90$ meV) bands. Our results are in reasonable agreement with neutron scattering experiments, and also to some data of Raman and infrared spectroscopy.

Submitted to PRL

Evidence of strong electron-phonon interaction in superconducting MgB2​ from electron tunneling

Abstract

Evidence of strong electron-phonon interaction in superconducting MgB $_{2}$ from electron tunneling