THEORY OF RESONANT RAMAN-SCATTERING FROM LOW-ENERGY COLLECTIVE EXCITATIONS OF INTERACTING ELECTRONS IN QUANTUM WIRES

The Raman spectra of quantum wires in the region of electronic intra-b and excitations are investigated using one- and two-band models based on the Luttinger approximation with spin. Structures related to charge and spin density modes are identified, and analyzed with respect to t heir behavior with photon energy and temperature. It is found that the ion-energy peaks in the polarized spectra, close to resonance that ar e commonly assigned to ''single particle excitations'', can be interpr eted as the signature of spin density excitations. A broad structure i n the resonant depolarized spectrum is predicted above the frequency o f the spin density excitations. This is due to simultaneous but indepe ndent propagation of spin and charge density modes. The results, when compared with experiment, show, that the electronic collective excitat ions of quantum wires at low energies are characteristic for a non-Fer mi liquid.