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Merging of single-particle levels and non-Fermi-liquid behavior of finite Fermi systems
V A Khodel1, J W Clark, Haochen Li
1Russian Research Centre Kurchatov Institute, Moscow, 123182, Russia.
Abstract:
We examine the problem of finite Fermi systems having a degenerate single-particle spectrum and show that the Landau approach, applied to such a system, admits the possibility of merging single-particle levels. It is demonstrated that the opportunity for this behavior is widespread in quantum many-body systems. The salient feature of the phenomenon is the occurrence of nonintegral quasiparticle occupation numbers, leading to a radical alteration of the standard quasiparticle picture. Implications of this alteration are considered for nuclear, atomic, and solid-state systems.
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