Fluctuations in the level density of a Fermi gas

P. Leboeuf 1, A. G. Monastra 2, A. Relano 3

Physical Review Letters 94 (2005) 102502

We present a theory that accurately describes the counting of excited states of a noninteracting fermionic gas. At high excitation energies the results reproduce Bethe\'s theory. At low energies oscillatory corrections to the many--body density of states, related to shell effects, are obtained. The fluctuations depend non-trivially on energy and particle number. Universality and connections with Poisson statistics and random matrix theory are established for regular and chaotic single--particle motion.

  • 1. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud
  • 2. Institut fur Theoretische Physik,
    Technische Universitat Dresden
  • 3. Departamento de Fisica Atomica, Molecular y Nuclear,
    Universidad Complutense de Madrid