In situ monitoring of quantum conductance in electrodeposited magnetic point contacts

Electrodeposition of Ni over electrodes initially separated by less than 100 nm has made possible the study of the conductance across increasingly smaller gaps between two magnetic materials. In situ measurements of the inter-electrode impedance showed conductance steps at multiples of e(2) / h, confirming the absence of spin degeneracy in ferromagnetic nanocontacts. No magnetoresistance larger than 10% for conductance values smaller than 50 e(2) / h was observed during the contact growth or dissolution under a sweeping external magnetic field.