The Hamiltonian of an king quantum chain with a square-root-increasing transverse magnetic field is exactly diagonalized and its spectrum determined by the zeros of Charlier polynomials. We compute also the magnetization at zem temperature as a function of the position in closed form.

FeSi 2 -based light-emitting devices were prepared by growing continuous and highly oriented -FeSi 2 films on Si(111) substrates using RF magnetron sputtering deposition with an Fe target. Response characterization of electroluminescence (EL) was carried out by measuring the rise time of the EL signal at room temperature, giving a characteristic time of approximately 15 ns for the device size of 1.5 mm Â1.5 mm. Temperature-dependent EL measurement was carried out from 10 K to 300 K and it was found that a 1.5 mm band EL signal underwent thermal quenching with an active energy of 0:11AE0:01 eV, whereas a 1.1 mm band EL signal appeared at around 200 K and its intensity increased with temperature, indicating a spatial change in emission area. The use of n-type -FeSi 2 as an active layer is proposed based on the consideration of current injection mode.

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