Observations were made of quantum oscillations in single crystals. Three de Haas-van Alphen frequencies were clearly resolved. A comparison with band structure calculations strongly suggested that 2 of these came from a single warped Fermi surface tube along the c-direction, and that the third arose from cylindrical sections of an in-plane honeycomb network. The measured values of the effective mass ranged from 0.44 to 0.68me. By comparing these with calculated band masses, it was found that the electron-phonon coupling strength was a factor of approximately 3 larger for the c-axis tube orbits than for the in-plane network orbit; in accord with microscopic calculations.

De Haas-Van Alphen Effect in Single Crystal MgB2. E.A.Yelland, J.R.Cooper, A.Carrington, N.E.Hussey, P.J.Meeson, S.Lee, A.Yamamoto, S.Tajima: Physical Review Letters, 2002, 88[21], 217002 (3pp)