2008/08/21 by T. Papenbrock, Hans A. Weidenmüller, H. A. Weidenmueller
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum chaos and dynamical systems #Quantum many-body systems #nucl-th
paper · pdf · doi:10.1103/physrevc.78.054305
published as Phys.Rev.C78:054305,2008 · 12 pages, 1 figure
arxiv created 2008/08/21 · openalex publication_date 2008/11/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate analytically and numerically a random-matrix model for m fermions occupying \ensuremathℓ1 single-particle states with positive parity and \ensuremathℓ2 single-particle states with negative parity and interacting through random two-body forces that conserve parity. The single-particle states are completely degenerate and carry no further quantum numbers. We compare spectra of many-body states with positive and with negative parity. We show that in the dilute limit defined by m,\ensuremathℓ1,2\ensuremath→\ensuremath∞ and m/\ensuremathℓ1,2\ensuremath→0, ground states with positive and negative parity occur with equal probability. Differences in the ground-state probabilities are, thus, a finite-size effect and are mainly due to different dimensions of the Hilbert spaces of either parity.