Proton removal-induced positive and negative magnetoresistance in cobalt heme analogs

By applying nonequilibrium Green's functions in combination with the density functional theory, we investigate the effect of the spin state transition induced by proton removal on the spin-polarized transport properties of molecular junctions incorporating cobalt heme analogs. Our study demonstrates that there is a drastic change in the resistance values when the spin state transition of cobalt heme analogs is triggered. As a consequence, a significant magnetoresistance of up to similar to 764% is observed. Moreover, a transition from negative magnetoresistance to positive magnetoresistance is also observed when the bias potential applied in the molecular junctions is tuned. Our results may be helpful for developing the interdisciplinary field of molecular protonics and spintronics.