AI 中文总结
研究双层系统中从声子-等离子体介导超导到声子介导超导的演化，采用埃利亚什贝格理论，通过研究随HL质量增加时$T_c$的变化来探索转变，还研究了任意质量比下的非绝热效应并给出$T_c$与频率截止的函数关系。
AI 中文摘要
受范德华异质结构最新进展的启发，我们采用埃利亚什贝格理论重新审视了由轻层（LL）和重层（HL）组成的双层系统中超导的声子-等离子体机制。HL中虚等离子体的交换可导致LL中电子之间时间延迟的吸引相互作用，我们通过随机相位近似下双层系统中的屏蔽相互作用对其进行建模。通过研究随着HL质量相对于LL中电子质量增加几个数量级时超导转变温度（$T_c$）的演化，我们探索了从声子-等离子体介导的超导到声子介导的超导的转变。较低的HL质量对应双层声子-等离子体，而后者更接近声子介导的强延迟配对的玻恩-奥本海默 regime。已知重HL质量极限由于两层各自质量的小比率而服从米格达尔定理。我们通过在埃利亚什贝格理论中使用频率截止来系统地研究任意质量比下无小参数的非绝热效应，并给出$T_c$作为该截止的函数。
英文摘要
Motivated by recent developments in van der Waals heterostructures, we revisit the acoustic plasmon mechanism of superconductivity in bilayer systems composed of a light layer (LL) and heavy layer (HL) by employing Eliashberg theory. The exchange of virtual plasmons in the HL can lead to a retarded in time attractive interaction between electrons of LL that we model through the screened interaction in the bilayer system within the random phase approximation. We explore the evolution from acoustic plasmon mediated superconductivity to phonon mediated superconductivity by studying the evolution of $T_c$ as the HL mass is increased by a few orders of magnitude compared with the electronic mass in LL. The lower HL mass corresponds to the bilayer acoustic plasmon, while the latter regime is closer to the Born-Oppenheimer regime of acoustic phonon mediated strongly retarded pairing. The heavy HL mass limit is known to obey Migdal's theorem by virtue of the small ratio of the two individual layer masses. We study the nonadiabatic effects for the arbitrary mass ratio with no small parameter systematically by using a frequency cut off in the Eliashberg theory, providing $T_c$ as a function of this cut off.
Comments7 pages, 3 figures
