title: de Haas-van Alphen effect in single crystal MgB2.
abstract: We report observations of quantum oscillations in single crystals of the high temperature superconductor MgB2. 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 to calculated band masses, we find that the electron-phonon coupling strength lambda is a factor of approximately 3 larger for the c-axis tube orbits than for the in-plane network orbit, in accord with recent microscopic calculations.
authors.affiliation: Interdisciplinary Research Centre in Superconductivity and Department of Physics, University of Cambridge, Madingley Road, Cambridge CB3 0HE, United Kingdom.
authors.forename: E A
authors.initials: EA
authors.lastname: Yelland
authors.forename: J R
authors.initials: JR
authors.lastname: Cooper
authors.forename: A
authors.initials: A
authors.lastname: Carrington
authors.forename: N E
authors.initials: NE
authors.lastname: Hussey
authors.forename: P J
authors.initials: PJ
authors.lastname: Meeson
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: A
authors.initials: A
authors.lastname: Yamamoto
authors.forename: S
authors.initials: S
authors.lastname: Tajima