Cross-over between collective and independent-particle excitations in quasi-2D electron gas with one filled miniband

Abstract

While it has been recently demonstrated that, for quasi-2D electron gas (Q2DEG) with one filled miniband, the dynamic exchange $f_x$ and Hartree $f_H$ kernels cancel each other in the low-density regime $r_s\to \infty$ (by half and completely, for the spin-neutral and fully spin-polarized cases, respectively), here we analytically show that the same happens at arbitrary densities at short distances. This motivates us to study the confinement dependence of the excitations in Q2DEG. Our calculations unambiguously confirm that, at strong confinements, the time-dependent exact exchange excitation energies approach the single-particle Kohn-Sham ones for the spin-polarized case, while the same, but less pronounced, tendency is observed for spin-neutral Q2DEG.

4 pages, 4 figures

References in corpus (5)

• Real-time electron dynamics with exact-exchange time-dependent density-functional theory
• Collapse of the Electron Gas to Two Dimensions in Density Functional Theory
• Three- to two-dimensional crossover in time-dependent density-functional theory
• Exact "exact exchange" potential of two- and one-dimensional electron gases beyond the asymptotic limit
• Quasi-low-dimensional electron gas with one populated band as a testing ground for time-dependent density-functional theory