Spin structure of many-body systems with two-body random interactions - art. no. 014307

We investigate the spin structure of many-fermion systems with a spin-conse rving two-body random inter action. We find a strong dominance of spin-0 gr ound states and considerable correlations between energies and wave functio ns of low-lying states with different spin, but no indication of pairing. T he spectral densities exhibit spin-dependent shapes and widths, and depend on the particle density as well as on the relative strengths of the spin-0 and spin-1 couplings in the two-body random matrix. The spin structure of l ow-lying states can largely be explained analytically.