The effective mass and g-factor of the strongly correlated 2-D electron fluid. Evidence for a coupled-valley condensate in the Si system

TL;DR

This paper presents a non-perturbative analytic calculation of the effective mass and g-factor in strongly correlated 2-D electron fluids, revealing a coupled-valley condensate in silicon systems at a critical density.

Contribution

It introduces a new analytic approach to compute effective mass and g-factor, demonstrating a coupled-valley condensate in Si 2D electron systems at a specific density.

Findings

Good agreement with experimental data for GaAs and Si systems.

g* is enhanced in GaAs, while m* is enhanced in Si.

Identification of a coupled-valley condensate at a critical density.

Abstract

The effective mass m*, and the Lande g-factor of the uniform 2-D electron fluid (2DEF) are calculated as a function of the spin polarization zeta, and the density parameter r_s, using a non-perturbative analytic approach. Our theory is in good accord with the m*g* data of Zhu et al. for zeta=0 for the GaAs-2DEF, and striking agreement with the data of Shashkin et al for the Si-2DEF. While g* is enhanced in GaAs, m* is enhanced in Si. The latter arises from singlet-pair excitations in the two valleys forming a coupled-valley state occurring at the critical density of ~1.10^{11}$ e/cm^2.