A theorem on the single particle energy in a Fermi gas with interaction

1958
14 pages
Published in:
  • Physica 24 (1958) 363-376

Citations per year

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Abstract: (Elsevier)
This paper investigates single particle properties in a Fermi gas with interaction at the absolute zero of temperature. In such a system a single particle energy has only a meaning for particles of momentum ‖ k ‖ close to the Fermi momentum k F . These single particle states are metastable with a life-time approaching infinity in the limit ‖ k ‖ → k F . The limiting value of the energy is called the Fermi energy E F . As a special case of a more general theorem, it is shown that for a system with zero pressure (i.e. a Fermi liquid at absolute zero) the Fermi energy E F is equal to the average energy per particle E 0 / N of the system. This result should apply both to liquid He 3 and to nuclear matter.