发表机构
Université de Sherbrooke（舍布鲁克大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究用重整化群方法分析准一维双带电子-声子模型中电荷密度波与超导的竞争，发现量子临界增强可产生超导穹顶，并探讨多带效应对超导温度等的影响。
AI 中文摘要
我们应用重整化群方法研究由电子-声子相互作用耦合的两个准一维紧束缚电子带中电荷密度波与超导相之间的相互作用。电子和声子能量尺度被嵌入到有限温度下的双截断标度方案中，用于电子间带内和带间声子介导相互作用的重整化群流动方程。在单圈水平上，推导了覆盖小和大声子频率的绝热和反绝热域的不同重整化区域。由此获得了作为电子谱嵌套受挫函数的有限温度相图。给出了电荷密度波和超导有序态叠加的可能性。发现了由电荷密度波有序涨落对库珀配对的量子临界增强所产生的超导穹顶的出现。讨论了电子结构的多带特性对超导有序温度、量子临界性和同位素效应的影响。
英文摘要
We apply the renormalization group method to examine the interplay between the charge density-wave and superconductivity phases in two quasi-one-dimensional tight-binding electronic bands coupled by the electron-phonon interaction. The electronic and phonon energy scales are embedded in a two-cutoff scaling scheme at finite temperature for the renormalization group flow equations of intra- and inter-band phonon-mediated interactions between electrons. At the one-loop level different regimes of renormalization are derived covering both the adiabatic and antiadiabatic domains for small and large phonon frequencies. Finite temperature phase diagrams as a function of nesting frustration of the electron spectrum are thus obtained. The possibilities for superimposed charge density-wave and superconducting ordered states are given. The emergence of domes of superconductivity resulting from quantum critical reinforcement of Cooper pairing by charge density-wave order fluctuations is found. The impact of the multiband character of the electronic structure on the ordering temperature of superconductivity, quantum criticality, and isotope effect is discussed.
Comments17 pages, 11 figures
