2026-04-13T15:00:04Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/164222026-01-30T08:05:49Zcom_2072_1033col_2072_452950

Ferromagnetic transition of a two-component Fermi gas of hard spheres Arias de Saavedra, F. Mazzanti Castrillejo, Fernando Pablo Boronat Medico, Jordi Polls, A. Àrees temàtiques de la UPC::Física Ferromagnetism Electron gas GROUND-STATE LIQUID-HE-3 HELIUM ENERGY Ferromagnetisme Electrons--Distribució We use microscopic many-body theory to analyze the problem of itinerant ferromagnetism in a repulsive atomic Fermi gas of hard spheres. Using simple arguments we show that the available theoretical predictions for the onset of the ferromagnetic transition predict a transition point at a density (kF a ∼ 1) that is too large to be compatible with the universal low-density expansion of the energy. We present variational calculations for the hard-sphere Fermi gas, in the framework of Fermi hypernetted chain theory, that shift the transition to higher densities (kF a ∼ 1.8). Backflow correlations, which are mainly active in the unpolarized system, are essential for this shift. Postprint (published version) 2012-03-12 Article http://pra.aps.org/abstract/PRA/v85/i3/e033615 http://creativecommons.org/licenses/by-nc-nd/3.0/es/ Open Access Attribution-NonCommercial-NoDerivs 3.0 Spain