We report observations of quantum oscillations in single crystals of the high temperature superconductor MgB_2. Three de Haas-van Alphen frequencies are clearly resolved. Comparison with band structure calculations strongly suggests that two of these come from a single warped Fermi surface tube along the c direction, and that the third arises from cylindrical sections of an in-plane honeycomb network. The measured values of the effective mass range from 0.44-0.68 m_e. By comparing these with band masses calculated recently by three groups, we find that the electron-phonon coupling strength lambda, is a factor \~3 larger for the c-axis tube orbits than for the in-plane network orbit, in accord with recent microscopic calculations.
@article{arxiv.cond-mat/0112392,
title = {de Haas-van Alphen effect in single crystal MgB_2},
author = {E. A. Yelland and J. R. Cooper and A. Carrington and N. E. Hussey and P. J. Meeson and S. Lee and A. Yamamoto and S. Tajima},
journal= {arXiv preprint arXiv:cond-mat/0112392},
year = {2009}
}
Comments
4 pages (revtex 4) including figures. Accepted for Publication in Phys. Rev. Lett