Diffusion Monte Carlo study of a valley degenerate electron gas and application to quantum dots
Abstract
A many-flavor electron gas (MFEG) in a semiconductor with a valley degeneracy ranging between 6 and 24 was analyzed using diffusion Monte Carlo (DMC) calculations. The DMC results compare well with an analytic expression derived by one of us [Phys. Rev. B 78, 035111 (2008)] for the total energy to within 1% over an order of magnitude range of density, which increases with valley degeneracy. For Bi2Te3 (six-fold valley degeneracy) the applicable charge carrier densities are between 7*10^19cm^{-3} and 2*10^20cm^{-3}. DMC calculations distinguished between an exact and a useful approximate expression for the 24-fold degenerate MFEG polarizability for wave numbers 2p_F<q<7p_F. The analytical result for the MFEG is generalized to inhomogeneous systems by means of a gradient correction, the validity range of this approach is obtained. Employed within a density functional theory calculation this approximation compares well with DMC results for a quantum dot.
Keywords
Cite
@article{arxiv.0810.5642,
title = {Diffusion Monte Carlo study of a valley degenerate electron gas and application to quantum dots},
author = {G. J. Conduit and P. D. Haynes},
journal= {arXiv preprint arXiv:0810.5642},
year = {2009}
}
Comments
15 pages, 7 figures, PRB (to appear)