Ground states of large quantum dots in magnetic fields

One-dimensional Lieb-Oxford bounds

We investigate and prove Lieb-Oxford bounds in one dimension by studying convex potentials that approximate the ill-defined Coulomb potential. A Lieb-Oxford inequality establishes a bound of the indirect interaction energy for electrons in terms of the one-body particle density ρ_ψ of a wave function ψ. Our results include modified soft Coulomb potential and regularized Coulomb potential. For these potentials, we establish Lieb-Oxford-type bounds utilizing logarithmic expressions of the particle density. Furthermore, a previous conjectured form I_xc(ψ)≥-C₁∫_Rρ_ψ(x)²dx is discussed for different convex potentials.

Prediction of quantum dot characteristics through universal scaling relations

We derive scaling relations for the electrochemical potential and addition energy of 2D quantum dots charged with N electrons. In the derivation we apply the Thomas-Fermi theory for the harmonic model of a quantum dot in the effective mass approximation. We demonstrate that the resulting scaling relations yield excellent agreement with measured chemical potentials and addition energies for both lateral and vertical quantum dots. Moreover, we show that the scaling relation has predictive power in estimating the confinement strength and the number of electrons trapped in the quantum dot.

Construction of the B88 Exchange-Energy Functional in Two Dimensions

We construct a generalized-gradient approximation for the exchange-energy density of finite two-dimensional systems. Guided by nonempirical principles, we include the proper small-gradient limit and the proper tail for the exchange-hole potential. The observed performance is superior to that of the two-dimensional local-density approximation, which underlines the usefulness of the approach in practical applications.

Lower bounds on the exchange-correlation energy in reduced dimensions

Bounds on the exchange-correlation energy of many-electron systems are derived and tested. By using universal scaling properties of the electron-electron interaction, we obtain the exponent of the bounds in three, two, one, and quasione dimensions. From the properties of the electron gas in the dilute regime, the tightest estimate to date is given for the numerical prefactor of the bound, which is crucial in practical applications. Numerical tests on various low-dimensional systems are in line with the bounds obtained and give evidence of an interesting dimensional crossover between two and one dimensions.