Spin polarized electrons in a metallic quantum wire

Abstract

We obtain explicit expressions for the spin-resolved density response functions of a spin polarized metallic quantum wire by including the first-order exchange and self-energy contributions to the random-phase approximation. These are used to calculate the spin-resolved static structure factors, pair-correlation functions, and correlation energy of the system for various values of the spin-polarization parameter ζ. The inclusion of first-order correction is found to bring the present approximate theory in overall very good agreement with the recent quantum Monte Carlo simulations by Shulenburger et al. [L. Shulenburger, M. Casula, G. Senatore, R.M. Martin, J. Phys. A 42, 214021 (2009)]. Particularly, we find excellently close results for the fully spin-polarized (i.e., ζ = 1) electrons for even larger coupling (r s ~ 4), implying a fairly good description of exchange correlations. Interestingly, there is no crossover found from para- to ferro-magnetic ground state. The static charge and spin susceptibilities, and spin sound are obtained analytically and found to be in good agreement with the available quantum Monte Carlo simulations. Furthermore, we present results for the wavevector dependent static charge density, spin density, and charge-spin density susceptibilities for some wire parameters. The dispersion of spin sound has also been obtained and found to be strongly dependent on wire width and density parameter.