Focused-ion-beam-fabricated nanoscale magnetoresistive ballistic sensors

In this letter, authors demonstrate magnetoresistance of the order of 18% at room temperature for a focused-ion-beam-fabricated nanoconstriction with critical dimensions of the order of 35nm⁠. The main purpose of this work is to show that focused ion beam (FIB)-fabricated nanoconstrictions are relatively reproducible and thus could be further developed to obtain substantially larger magnetoresistance. Magnetoresistance is expected to increase if critical dimensions of nanoconstrictions are further reduced. The proposed focused-ion-beam-fabricated nanoconstrictions could be also used as devices to study the electron “ballistic” regime in the emerging fields of Spintronics and magnetoresistive random access memory (MRAM).