Ground state of a quasi-two-dimensional electron gas

The ground state of a quasi-two-dimensional electron gas (Q-2DEG) is investigated within a framework of the local spin density approximation (LSDA) with Perdew–Zunger type exchange-correlation energy. The ground state in a Q-2DEG is given as a function of film thickness and electron density. The Wigner rod ground state in a very thin film with low electron areal density is discussed in detail. In addition, the ground state of a two-dimensional electron gas (2DEG) is investigated using the LSDA with Tanatar–Ceperley and Attaccalite–Moroni–Georgi–Bachelet types of exchange-correlation energy. The ground state is found to show a phase transition from a nonmagnetic fluid to a spin-fully-polarized ferromagnetic Wigner ribbon with decreasing areal density. The difference between a 2DEG and a Q-2DEG with infinitesimal film thickness is discussed.