Spontaneous magnetization of the 2D electron gas

We discuss the occurrence of spontaneous spin-polarization in a 2D electron gas, as predicted by fixed-node DMC simulations of unprecedented accuracy, in which errors from finite time step, number of particles, and number of walkers have been systematically extrapolated out. We have performed simulations with both Slater-Jastrow and backflow nodes, which confirm a stability range for the fully spin-polarized phase at densities achievable nowadays in 2-dimensional hole gases in semiconductor heterostructures. We find no evidence for a phase with partial spin polarization, in spite of a huge enhancement of the spin susceptibility of the unpolarized phase at the magnetic transition. (C) 2001 Elsevier Science B.V. All rights reserved.