Science. 1991 Nov 8;254(5033):842-5. doi: 10.1126/science.254.5033.842.
Quantitative theories of superconductivity in alkali-doped C(60) require an accurate and detailed description of the Fermi surface. First-principles calculations of Fermi-surface properties and electronic parameters for K(3)C(60), the prototype fulleride-superconductor, are reported. The Fermi surface has two sheets; the first is free-electron-like, and the second is multiply-connected, forming two interlocked symmetry-equivalent pieces that never touch. The calculated (clean limit) London penetration depth is Lambda = 1600 A. Comparing the Fermi velocity with the experimental coherence length leads to a superconducting pairing strength lambda approximately 5, indicating very strong coupling. Partial nesting in the second Fermi-surface sheet may favor coupling to short-wavelength q,0,0 optic modes.
碱掺杂 C(60)超导电性的定量理论需要对费米面进行准确和详细的描述。本文报道了富勒烯超导母体 K(3)C(60)的费米面性质和电子参数的第一性原理计算结果。费米面由两个面组成，第一个是自由电子型，第二个是多连通的，形成两个相互交织的对称等效部分，从不接触。计算出的（清洁极限）伦敦穿透深度为 Lambda = 1600 A。将费米速度与实验相干长度进行比较，得到超导配对强度 lambda 约为 5，表明耦合非常强。第二个费米面片中的部分嵌套可能有利于与短波长 q，0，0 光学模式耦合。
