QUANTUM-CLASSICAL CORRESPONDENCE IN ENERGY SPACE - 2 INTERACTING SPINPARTICLES

The Hamiltonian conservative system of two interacting particles has b een considered both in classical and quantum description. The quantum model has been realized using a symmetrized two-particle basis reorder ed in the unperturbed energy. The main attention is paid to the struct ure of chaotic eigenfunctions (EF's) and to the local spectral density of states (LDOS). A remarkable correspondence has been found for the shapes of EF's and the LDOS in the energy representation to their clas sical counterparts. Comparison with the band random matrix theory pred ictions has revealed quite significant differences, which are due to t he dynamical nature of the model. On the other hand, a partial agreeme nt is found by inserting randomness ad hoc in the dynamical model for two-body matrix elements. This shows that, at least for small number o f particles, care must be taken when classical correlations are neglec ted. The question of quantum localization in the energy space is discu ssed for both the dynamical and random models.