声子线型对固态氢超导性的巨大影响
Large impact of phonon lineshapes on the superconductivity of solid hydrogen
AI总结：
本研究探讨了非洛伦兹声子线型对高压固态氢超导性的影响，通过从头计算完整声子谱函数发现声子软化与线展宽对超导临界温度T_C分别产生增强和降低作用，总体提升了T_C估计值，并揭示了450-500 GPa下氢分子相VI的超导性，解释了理论与实验的分歧。
AI中文摘要：
声子非谐性在决定高压氢化物的稳定性和振动性质方面起着至关重要的作用。此外，强非谐性会使声子准粒子图像失效，从而质疑在这些材料系统中对超导性进行建模的标准方法。在这项工作中，我们展示了非洛伦兹声子线型对高压固态氢超导性的影响。我们考虑完整的声子谱函数，从头计算了超导临界温度 T$_\mathrm{C}$，并表明它总体上增强了 T$_\mathrm{C}$ 的估计值。谱函数中表现出的由非谐性引起的声子软化提高了临界温度的估计值，而由声子-声子相互作用引起的声子线展宽则降低了该估计值。我们的计算还揭示，氢在 450 至 500 GPa 压力下的 $Cmca-12$ 分子相 VI 中出现超导性，并解释了先前理论结果与实验之间的分歧。
英文摘要：
Phonon anharmonicity plays a crucial role in determining the stability and vibrational properties of high-pressure hydrides. Furthermore, strong anharmonicity can render phonon quasiparticle picture obsolete questioning standard approaches for modeling superconductivity in these material systems. In this work, we show the effects of non-Lorentzian phonon lineshapes on the superconductivity of high-pressure solid hydrogen. We calculate the superconducting critical temperature T$_\mathrm{C}$ \emph{ab initio} considering the full phonon spectral function and show that it overall enhances the T$_\mathrm{C}$ estimate. The anharmonicity-induced phonon softening exhibited in spectral functions increases the estimate of the critical temperature, while the broadening of phonon lines due to phonon-phonon interaction decreases it. Our calculations also reveal that superconductivity emerges in hydrogen in the $Cmca-12$ molecular phase VI at pressures between 450 and 500 GPa and explain the disagreement between the previous theoretical results and experiments.
