Electronic and magnetic properties of thin film with intermediate electron density

The ground state of a thin film with intermediate electron density is theoretically investigated using the planar uniform jellium model as the positive charge background within a framework of the local spin density approximation, to which the Janak–Moruzzi–Williams-type exchange-correlation energy is applied. With an increase of the Wigner sphere radius, rs, in the ground state, electrons become self-confined to the valleys of a periodic potential, along the perpendicular axis to the surfaces, induced by the electrons. Such a self-confined state is considered to be a one-dimensional (1D) crystal, in which the electronic state is a spin-fully polarized ferromagnetic electron gas along the parallel directions to the surfaces. The ground state of a thin film with an intermediate electron density, rs=40 (in the atomic units), is found to be a fully polarized ferromagnetic 1D crystal, in which the number of peaks in the electron density profile increases as the film thickness is increased. The role of the 1D crystal in the ground state of a three-dimensional interacting electron gas is discussed.