Resonant Raman scattering by collective modes of the one-dimensional electron gas

TL;DR

This paper demonstrates that the low-energy peak in resonant Raman spectra of quantum wires is due to intra-band collective spin excitations, revealing the interplay of spin and charge modes in one-dimensional electron systems.

Contribution

It provides a new interpretation of Raman spectral features as signatures of collective spin excitations in quantum wires, linking experimental observations to theoretical models.

Findings

Low-energy Raman peak linked to spin excitations

Predicted broad maximum above spin density excitation frequency

Distinct propagation of spin and charge density modes

Abstract

We show that the low-energy peak in the polarized resonant Raman spectra of quantum wires, which is commonly associated with ``single particle excitations'', can be interpreted as signature of intra-band collective spin excitations. A broad maximum in the resonant depolarized spectra is predicted to exist above the frequency of the spin density excitation, due to simultaneous but independent propagation of spin- and charge-density modes.