Modelling a spin-selective interface between ferromagnetic electrodes and a carbonnanotube—towards the enhanced giant magnetoresistance effect

Abstract

The effect of interface conditions on the giant magnetoresistance (GMR) is studied. It isshown that the GMR changes drastically in the presence of extra magnetic monolayers atthe ferromagnetic electrodes. The monolayers may make the spin-dependent conductancechannels nearly or completely closed if they are antiferromagnetically exchangecoupled to the electrodes. It is shown that the conductance spectrum of the devicereflects, to a large degree, the internal band structure of the nanotube. Thereforethe GMR effect is quite sensitive to the relative bands’ line-up of electrodes andthe nanotube and it may be tuned by a gate voltage applied to the nanotube.