Towards exact solutions for the superconducting $T_c$ induced by electron-phonon interaction
| Autor: | Xiao-Yin Pan, Guo-Zhu Liu, Zhao-Kun Yang, Jing-Rong Wang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Superconductivity
Physics Condensed Matter - Materials Science Strongly Correlated Electrons (cond-mat.str-el) Computation Condensed Matter - Superconductivity Propagator Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology Electron 021001 nanoscience & nanotechnology Coupling (probability) 01 natural sciences Integral equation Superconductivity (cond-mat.supr-con) Condensed Matter - Strongly Correlated Electrons Quantum mechanics Condensed Matter::Superconductivity 0103 physical sciences Homogeneous space Vertex (curve) 010306 general physics 0210 nano-technology |
| Popis: | Electron-phonon interaction plays an important role in metals and can lead to superconductivity and other instabilities. Previous theoretical studies on superconductivity are largely based on the Migdal-Eliashberg theory, which neglects all the vertex corrections to electron-phonon coupling and breaks down in many unconventional superconductors. Here, we go beyond the Migdal-Eliashberg approximation and develop a nonperturbative Dyson-Schwinger equation approach to deal with the superconducting transition. Remarkably, we take into account all the vertex corrections by solving two coupled Ward-Takahashi identities derived from two global U(1) symmetries and rigorously prove that the fully renormalized electron propagator satisfies a self-closed integral equation that is directly amenable to numerical computations. Our approach works equally well in the weak and strong coupling regimes and provides an efficient method to determine superconducting $T_c$ and other quantities. As an application, our approach is used to investigate the high-$T_c$ superconductivity in one-unit-cell FeSe/SrTiO$_3$. 19 pages, 4 figures, published version |
| Databáze: | OpenAIRE |
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