Method of successive separation and summing of multiplicative diagrams of mass operator for the multi-level quasiparticle interacting with polarization phonons
The theory of renormalized energy spectrum of a multi-level quasiparticle interacting with polarization phonons at T = 0 K is developed within the Feynman-Pines diagram technique in a new approach. It permits a successive separation of multiplicative diagrams from non-multiplicative ones for all ord...
| Published in: | Condensed Matter Physics |
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| Main Authors: | , , , |
| Format: | Article |
| Language: | English |
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Yukhnovskii Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine
2019-09-01
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| Subjects: | |
| Online Access: | https://doi.org/10.5488/CMP.22.33703 |
| Summary: | The theory of renormalized energy spectrum of a multi-level quasiparticle interacting with polarization phonons at T = 0 K is developed within the Feynman-Pines diagram technique in a new approach. It permits a successive separation of multiplicative diagrams from non-multiplicative ones for all orders of mass operator, and their partial summing as well. The obtained mass operator is presented as a sum of branched chain fractions, which effectively take into account the multi-phonon processes. For the two-level quasiparticle it is shown that just the interlevel (non-diagonal) interaction with phonons fundamentally changes the properties of the spectrum. In the vicinity of all threshold energies, the quasi-equidistant phonon satellite bands (i.e., groups of energy levels) are formed. They correspond to the complexes of bound states of a quasi-particle with many phonons. |
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| ISSN: | 1607-324X 2224-9079 |