Green functions in the renormalized many-body perturbation theory for correlated and disordered electrons

• Видавець: Інститут фізики конденсованих систем НАН України
• Дата: 2006
• Автор: Janis, V.
• Формат: Стаття
• Мова: English
• Опубліковано: Інститут фізики конденсованих систем НАН України 2006
• Назва видання: Condensed Matter Physics
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/121351
• Цитувати: Green functions in the renormalized many-body perturbation theory for correlated and disordered electrons / V. Janis // Condensed Matter Physics. — 2006. — Т. 9, № 3(47). — С. 499–518. — Бібліогр.: 28 назв. — англ.

The ways of introducing and handling renormalizations in the many-body perturbation theory are reviewed. We stress the indispensable role the technique of Green functions plays in extrapolating the weak-coupling perturbative approaches to intermediate and strong couplings. We separately discuss mass and charge renormalizations. The former is incorporated in a self-consistent equation for the self-energy derived explicitly from generating Feynman diagrams within the Baym and Kadanoff approach. The latter amounts to self-consistent equations for two-particle irreducible vertices. We analyze the charge renormalization initiated by De Dominicis and Martin and demonstrate that its realization via the parquet approach may become a powerful and viable way of using the many-body diagrammatic approach reliably in non-perturbative regimes with cooperative phenomena induced by either strong interaction or strong static randomness.