Antiadiabatic Phonons, Coulomb Pseudopotential, and Superconductivity in Eliashberg—McMillan Theory
Antiadiabatic Phonons, Coulomb Pseudopotential, and Superconductivity in Eliashberg—McMillan Theory
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Eliashberg 中的抗绝热声子、库仑赝势和超导性——麦克米伦理论
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
M. V. Sadovskii
中科院分区：
文献类型：
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作者：
M. V. Sadovskii
在离散声子频率模型下，用Eliashberg-McMillan方法研究了反绝热声子对超导转变温度的影响.本文提出了一个普遍的超导转变温度Tc的表达式，它适用于一个（或几个）这样的声子成为反绝热的情况。我们研究了这些声子对库仑赝势μ* 的贡献。结果表明，反绝热声子对托尔马切夫对数没有贡献，其值仅由绝热声子的部分贡献决定。得到的结果进行了讨论的背景下，异常高的超导转变温度的FeSe单层STO的问题。
The influence of antiadiabatic phonons on the superconducting transition temperature is considered within Eliashberg-McMillan approach in the model of discrete set of (optical) phonon frequencies. A general expression for superconducting transition temperature Tc is proposed, which is valid in situation, when one (or several) of such phonons becomes antiadiabatic. We study the contribution of such phonons into the Coulomb pseudopotential μ*. It is shown that antiadiabatic phonons do not contribute to Tolmachev’s logarithm and its value is determined by partial contributions from adiabatic phonons only. The results obtained are discussed in the context of the problem of an unusually high superconducting transition temperature of the FeSe monolayer on STO.