Spectra of correlated many-electron systems: From a one- to a two-particle description
| Autor: | G. Rohringer |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Radiation 010304 chemical physics Fermi level 02 engineering and technology Electron 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics Spectral line Electronic Optical and Magnetic Materials symbols.namesake Pairing 0103 physical sciences symbols Valence bond theory Statistical physics Physical and Theoretical Chemistry 0210 nano-technology Ground state Pseudogap Spectroscopy Spin-½ |
| Zdroj: | Journal of Electron Spectroscopy and Related Phenomena. 241:146804 |
| ISSN: | 0368-2048 |
| DOI: | 10.1016/j.elspec.2018.11.003 |
| Popis: | State-of-the-art spectroscopic techniques allow for a comprehensive understanding of one-electron excitations in various physically interesting and/or technologically relevant materials. While for weakly-correlated systems the corresponding one-particle spectral function A(ω, k) contains essentially all information about their physical properties the situation is much more complicated in the presence of strong electronic correlations. In fact, in the latter case different theoretical treatments often lead to very different explanations of the origin of specific features in the spectrum. A typical example is the pseudogap in the cuprates, i.e., the momentum-selective suppression of spectral weight at the Fermi level, which has been related to spin, charge or (d-wave) pairing fluctuations by different authors. This ambiguity about the underlying physical mechanism at work can be overcome by considering two-particle correlation functions as they are able to describe the collective modes of the system and can be also related to certain ground state properties. In this work, we will present different theoretical approaches for analyzing the spectrum of correlated systems by exploiting the information contained in these two-particle correlation functions. For the specific case of the pseudogap these procedures have allowed us (1) to identify antiferromagnetic spin fluctuations as microscopic origin of this spectral feature which (2) can be related to the formation of a resonating valence bond ground state in the system. |
| Databáze: | OpenAIRE |
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