Fluctuations in the Level Density of a Fermi Gas
نویسندگان
چکیده
منابع مشابه
Fluctuations in the level density of a fermi gas.
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 nontrivially on energy and particle number. Universality and connections with P...
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We compute the level density of a two-component Fermi gas as a function of the number of particles, angular momentum, and excitation energy. The result includes smooth low-energy corrections to the leading Bethe term (connected to a generalization of the partition problem and Hardy-Ramanujan formula) plus oscillatory corrections that describe shell effects. When applied to nuclear level densiti...
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It has been shown by H. Bethe more than 70 years ago that the number of excited states of a Fermi gas grows, at high excitation energies Q, like the exponential of the square root of Q. This result takes into account only the average density of single particle (SP) levels near the Fermi energy. It ignores two important effects, namely the discreteness of the SP spectrum, and its fluctuations. W...
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To accurately measure the atom number variance it is necessary to eliminate patterns in the absorption images whose fluctuations increase the observed noise. Weak reflections of the probe beam from the walls of the glass cell and from optical elements in the imaging system can interfere with the probe beam itself, leading to spatial fluctuations in its intensity profile. To reduce interference ...
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ژورنال
عنوان ژورنال: Physical Review Letters
سال: 2005
ISSN: 0031-9007,1079-7114
DOI: 10.1103/physrevlett.94.102502