Tse J S, Yao Y, Tanaka K
Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Canada, S7N 5E2.
Phys Rev Lett. 2007 Mar 16;98(11):117004. doi: 10.1103/PhysRevLett.98.117004. Epub 2007 Mar 15.
From first-principles calculations, a high-pressure metallic phase of SnH(4) with a novel layered structure intercalated by "H(2)" units is revealed. This structure is stable at pressure between 70 and 160 GPa. A remarkable feature of this structure is the presence of soft modes in the phonon band structure induced by Fermi surface nesting and Kohn anomalies that lead to very strong electron-phonon coupling. The application of the Allen-Dynes modified McMillan equation with the calculated electron-phonon coupling parameter lambda shows that a superconducting critical temperature close to 80 K can be achieved at 120 GPa.
通过第一性原理计算，揭示了一种具有由“H₂”单元插入的新型层状结构的SnH₄高压金属相。这种结构在70至160 GPa的压力下是稳定的。该结构的一个显著特征是在声子能带结构中存在由费米面嵌套和科恩反常诱导的软模，这导致了非常强的电子 - 声子耦合。应用带有计算出的电子 - 声子耦合参数λ的艾伦 - 戴恩斯修正麦克米兰方程表明，在120 GPa时可以实现接近80 K的超导临界温度。
