Effects of inelastic spin-dependent electron transport through a spin nanostructure in a magnetic field

Abstract

The transport properties and current-voltage (I–V) characteristics of a system of spin dimers with antiferromagnetic coupling arranged between metallic contacts are investigated in the tight binding approximation using the Landauer-Buttiker formalism. It is shown that the s-d(f) exchange interaction between the spin moments of the electrons being transported and the spins of the nanostructure leads to the formation of a potential profile as well as its variation due to spin-flip processes. As a result, the spin-dependent transport becomes inelastic, and the transmission coefficient and the I–V characteristic are strongly modified. It is found that the application of a magnetic field induces additional transparency peaks in the spectral characteristic of the system and causes the colossal magnetoresistance effect.