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Merging of single-particle levels and non-Fermi-liquid behavior of finite Fermi systems

V. A. Khodel·J. W. Clark·Haochen Li·M. V. Zverev
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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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V. A. Khodel, J. W. Clark, Haochen Li, M. V. Zverev. 2007-01-05. Merging of single-particle levels and non-Fermi-liquid behavior of finite Fermi systems. https://doi.org/10.1103/physrevlett.98.216404

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