Spin-polarization transition in the two-dimensional electron gas

Author： Varsano D. Moroni S. Senatore G.

E-ISSN： 1286-4854|53|3|348-353

ISSN： 0295-5075

Source： EPL (EUROPHYSICS LETTERS), Vol.53, Iss.3, 2010-03, pp. : 348-353

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Abstract

We present a numerical study of magnetic phases of the 2D electron gas nearfreezing. The calculations are performed by diffusion Monte Carlo in the fixed-node approximation. At variance with the 3D case we find no evidence for thestability of a partially polarized phase. With plane wave nodes in the trialfunction, the polarization transition takes place at $r_\ab{s}=20$, whereas thebest available estimates locate Wigner crystallization around $r_\ab{s}=35$. Usingan improved nodal structure, featuring optimized backflow correlations, weconfirm the existence of a stability range for the polarized phase, althoughsomewhat shrunk, at densities achievable nowadays in 2-dimensional holegases in semiconductor heterostructures. The spin susceptibility of theunpolarized phase at the magnetic transition is approximately 30 times thePauli susceptibility.