Showing papers on "Mott insulator published in 1981"
TL;DR: In this article, the fourth order interactions among localized spins in an orbital-degenerate case (S > 1/2) are discussed as an expansion from the Mott insulator limit, with reference to a model for the electronic structure of NiS 2.
Abstract: Possible fourth order interactions among localized spins in an orbital-degenerate case ( S >1/2) are discussed as an expansion from the Mott insulator limit, with reference to a model for the electronic structure of NiS 2 . Then a phenomenological model to study the antiferromagnetic structure of NiS 2 is presented.
16 citations
5 citations
01 Jan 1981
TL;DR: In this paper, an electron-hole pair forms an exciton embedded in a ferromagnetic volume, the radius of which is large compared to the exciton Bohr radius.
Abstract: In a Mott insulator, excess charge carriers in narrow half-filled degenerate bands form spin polarons. An electron-hole pair forms an exciton embedded in a ferromagnetic volume, the radius of which is large compared to the exciton Bohr radius. If a wide conduction band lies in the Hubbard gap, the exciton radius can be large compared to the hole-polaron radius. Then, depending on the exciton concentration, a gas of excitonic molecules of an electron-hole plasma can be formed.
4 citations