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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 4 Issue 3 (1998) pp 357-367
Theory of resonant Raman scattering from low-energy collective excitations of interacting electrons in quantum wires
M. Sassetti (1), B. Kramer (2) (a)
(1) Istituto di Fisica di Ingegneria, INFM, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
(2) I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
Received: 25 March 1998 / Accepted: 3 June 1998
Abstract: The Raman spectra of quantum wires in the region of electronic intra-band 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 their behavior with photon energy and temperature. It is found that the low-energy peaks in the polarized spectra, close to resonance that are commonly assigned to "single particle excitations", can be interpreted as the signature of spin density excitations. A broad structure in the resonant depolarized spectrum is predicted above the frequency of the spin density excitations. This is due to simultaneous but independent propagation of spin and charge density modes. The results, when compared with experiment, show, that the electronic collective excitations of quantum wires at low energies are characteristic for a non-Fermi liquid.
PACS. 71.45.-d Collective effects - 78.30.-j Infrared and Raman spectra - 73.20.Dx Electron states in low-dimensional structures
(a) email: kramer@physnet.uni-hamburg.de
Article in PDF-Format (363 KB)
Online publication: August 17, 1998
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