Europhys. Lett.
Volume 71, Number 5, September 2005
Page(s) 776 - 782
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 03 August 2005
Europhys. Lett., 71 (5), pp. 776-782 (2005)
DOI: 10.1209/epl/i2005-10156-5

Observation of phonon structure in electron density of states of a normal metal

A. Knigavko1, J. P. Carbotte1 and F. Marsiglio2

1  Department of Physics and Astronomy, McMaster University Hamilton, Ontario, Canada, L8S 4M1
2  Department of Physics, University of Alberta - Edmonton, Alberta, Canada, T6J 2J1

received 29 April 2005; accepted in final form 5 July 2005
published online 3 August 2005

Within standard treatments of the interacting electron-phonon system the electron density of states (EDOS) shows no sign of the phonons when the system is in the normal state. On the other hand, emergence of a fine energy scale in the superconducting state makes the phonons readily observable in the EDOS and other spectroscopic quantities. Here we wish to re-examine the conditions under which phonon structure might be present in the normal state. Accounting for a finite, i.e. non-infinite, electronic bandwidth results in easily distinguishable phonon structure in the EDOS. We argue that for narrow-band metals, the resolution of photoemission spectroscopy is sufficient for resolving these structures. Manifestations of finite-band effects in $\chem{K_3C_{60}}$ are discussed.

71.10.Ay - Fermi-liquid theory and other phenomenological models.
71.38.-k - Polarons and electron-phonon interactions.
79.60.-i - Photoemission and photoelectron spectra.

© EDP Sciences 2005