1. Post-$GW$ theory and its application to pseudogap in strongly correlated system
- Author
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Li, Hui, Su, Yingze, Xiong, Junnian, Lin, Haiqing, Huang, Huaqing, and Li, Dingping
- Subjects
Condensed Matter - Strongly Correlated Electrons - Abstract
The $GW$ approximation is a widely used framework for studying correlated materials, but it struggles with certain limitations, such as its inability to explain pseudogap phenomena. To overcome these problems, we propose a systematic theoretical framework for Green's function corrections and apply it specifically to the $GW$ approximation. In this new theory, the screened potential is reconnected to the physical response function, i.e. the covariant response function proposed in \cite{cGW_2023}, rather than using the RPA formula. We apply our scheme to calculate Green's function, the spectral function, and the charge compressibility in the two-dimensional Hubbard model. Our scheme yields significant qualitative and quantitative improvements over the standard $GW$ method and successfully captures the pseudogap behavior., Comment: 13 pages, 5 figures
- Published
- 2024