Non-ergodic behaviour of the k-body embedded Gaussian random ensembles for bosons
Max-Planck-Institut für Kernphysik - D-69029
Accepted: 17 August 2001
We investigate the shape of the spectrum and the spectral fluctuations of the k-body embedded Gaussian ensemble for bosons in the dense limit, where the number of bosons while both k, the rank of the interaction, and l, the number of single-particle states, are kept fixed. We show that the relative fluctuations of the low spectral moments do not vanish in this limit, proving that the ensemble is non-ergodic. Numerical simulations yield spectra which display a strong tendency towards picket-fence-type. The wave functions also deviate from canonical random-matrix behaviour.
PACS: 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion / 05.30.Jp – Boson systems / 21.10.-k – Properties of nuclei; nuclear energy levels
© EDP Sciences, 2001