Multivalued dependence of the magnetoresistance on the quantized conductance in nanosize magnetic contacts

摘要

We calculate the quantized conductance of nanosize point contacts between twoferromagnets for different mutual orientations of the magnetic moments. It isfound that the magnetoresistance MR is a multivalued function of the quantizedconductance at the parallel alignment of the magnetizations sigma^F. This leadsus to the conclusion that experimentally observed large fluctuations of MRversus sigma^F are rather due to the conductance quantization than tomeasurement errors or a poor reproducibility of the results. Using the resultsof the calculations we are able to understand experimental data obtained byGarcia et al for MR of the magnetic nanocontacts.