Yelland E A, Cooper J R, Carrington A, Hussey N E, Meeson P J, Lee S, Yamamoto A, Tajima S
Interdisciplinary Research Centre in Superconductivity and Department of Physics, University of Cambridge, Madingley Road, Cambridge CB3 0HE, United Kingdom.
Phys Rev Lett. 2002 May 27;88(21):217002. doi: 10.1103/PhysRevLett.88.217002. Epub 2002 May 10.
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.
我们报告了高温超导体MgB₂单晶中量子振荡的观测结果。三个德哈斯-范阿尔芬频率清晰可辨。与能带结构计算结果的比较有力地表明，其中两个频率来自沿c方向的单个翘曲费米面管，而第三个频率则源于面内蜂窝状网络的圆柱截面。有效质量的测量值范围为(0.44 - 0.68)m(e)。通过将这些值与计算得到的能带质量进行比较，我们发现，与面内网络轨道相比，c轴管轨道的电子-声子耦合强度λ大约大3倍，这与最近的微观计算结果一致。
