The ground-state properties of the quasi-one-dimensional electron gas are determined theoretically within the quantum/dynamical version of the self-consistent mean-field approximation of Singwi, Tosi, Land, and Sjölander ͑the so-called qSTLS approach͒. The transverse motion of electrons is assumed to be confined by a harmonic potential. The calculated static structure factor, pair-correlation function, and correlation energy are compared directly with the recent findings of lattice regularized diffusion Monte Carlo simulation study due to Casula et al. It has been found that the qSTLS results are overall in better agreement with the simulation data than the predictions based upon static mean-field theories. Results for the dynamic local-field correction, dynamic structure factor, and plasmon excitation energy are also reported. The qSTLS approach is found to yield an inadequate description of the dynamic properties; for instance, the dynamic structure factor was seen to become negative over a range of frequencies. Our theoretical predictions, seen in conjunction with similar studies on the three-and two-dimensional electron systems, lead us to conclude that the correlation effects are relatively more pronounced in one-dimensional electron gas.
We have studied symmetric electron-electron and electron-hole bilayers to explore the stable homogeneous spin phase and the feasibility of inhomogeneous charge-/spin-density ground states. The former is resolved by comparing the ground-state energies in states of different spin polarizations, while the latter is resolved by searching for a divergence in the wavevector-dependent static charge/spin susceptibility. For this endeavour, we have used the dielectric approach within the self-consistent mean-field theory of Singwi et al. We find that the inter-layer interactions tend to change an abrupt spin-polarization transition of an isolated layer into a nearly gradual one, even though the partially spin-polarized phases are not clearly stable within the accuracy of our calculation. The transition density is seen to decrease with a reduction in layer spacing, implying a suppression of spin polarization by inter-layer interactions. Indeed, the suppression shows up distinctly in the spin susceptibility computed from the spin-polarization dependence of the ground-state energy. However, below a critical layer spacing, the unpolarized liquid becomes unstable against a charge-density-wave (CDW) ground state at a density preceding full spin polarization, with the transition density for the CDW state increasing on further reduction in the layer spacing. Due to attractive e-h correlations, the CDW state is found to be more pronounced in the e-h bilayer. On the other hand, the static spin susceptibility diverges only in the long-wavelength limit, which simply represents a transition to the homogeneous spin-polarized phase.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.