The stacked magnetic tunnel junctions (MTJs) are microfabricated into ferromagnetic single-electron tunneling devices (F-SETs) by using electron-beam lithography. The F-SETs have a couple of small MTJs (30×500 nm2 -0.1×100 μ m2), which are connected via a metallic nanowire. The large tunnel magnetoresistance ratio as much as 40% (at RT) and small junction area dependence of the RA (resistance×area) are obtained. The electrostatic energy of F-SETs estimated from the minimum junction area corresponds to the temperature of 1 K, which is high enough to observe Coulomb blockade phenomena in a dilution refrigerator.
ASJC Scopus subject areas
- Physics and Astronomy(all)