Paper detail

Robustness of the magnetoresistance of nanoparticle arrays

Recent work has found that the interplay between spin accumulation and Coulomb blockade in nanoparticle arrays results in peaky I-V and tunneling magnetoresistance (TMR) curves and in huge values of the TMR. We analyze how these effects are influenced by a polarization asymmetry of the electrodes, the dimensionality of the array, the temperature, resistance or charge disorder and long-range interactions. We show that the magnitude and voltage dependence of the TMR does not change with the dimensionality of the array or the presence of junction resistance disorder. A different polarization in the electrodes modifies the peak shape in the I-V and TMR curves but not their order of magnitude. Increasing the temperature or length of the interaction reduces to some extent the size of the peaks, being the reduction due to long-range interactions smaller in longer arrays. Charge disorder should be avoided to observe large TMR values.