Spin-dependent dipole excitation in alkali-metal nanoparticles
Abstract
We study the spin-dependent electronic excitations in alkali-metal nanoparticles. Using numerical and analytical approaches, we focus on the resonances in the response to spin-dependent dipole fields. In the spin-dipole absorption spectrum for closed-shell systems, we investigate in detail the lowest-energy excitation, the "surface paramagnon" predicted by L. Serra et al. [Phys. Rev. A 47, R1601 (1993)]. We estimate its frequency from simple assumptions for the dynamical magnetization density. In addition, we numerically determine the dynamical magnetization density for all low-energy spin-dipole modes in the spectrum. Those many-body excitations can be traced back to particle-hole excitations of the noninteracting system. Thus, we argue that the spin-dipole modes are not of collective nature. In open-shell systems, the spin-dipole response to an electrical dipole field is found to increase proportionally with the ground-state spin polarization.
Keywords
Cite
@article{arxiv.0905.2076,
title = {Spin-dependent dipole excitation in alkali-metal nanoparticles},
author = {Yue Yin and Paul-Antoine Hervieux and Rodolfo A. Jalabert and Giovanni Manfredi and Emmanuel Maurat and Dietmar Weinmann},
journal= {arXiv preprint arXiv:0905.2076},
year = {2009}
}
Comments
12 pages, 9 figures