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.

15 pages, 7 figures, PRB (to appear)

References in corpus (8)

• Jastrow correlation factor for atoms, molecules, and solids
• Ultracold fermions and the SU(N) Hubbard model
• Spin-orbit interaction effect in the electronic structure of \BiTe \ observed by angle-resolved photoemission spectroscopy
• Superfluidity and magnetism in multicomponent ultracold fermions
• BCS pairing in Fermi systems with several flavors
• A molecular state of correlated electrons in a quantum dot
• Mapping of the Anisotropic Two-channel Anderson Model onto a Fermi-Majorana bi-Resonant Level Model
• Many-flavor electron gas approach to electron-hole drops