Observation of full shot noise in CoFeB/MgO/CoFeB-based magnetic tunneling junctions

The electron transport through the CoFeB/MgO/CoFeB-based magnetic tunneling junction (MTJ) was studied by the shot noise measurement. The obtained Fano factor to characterize the shot noise is very close to unity, indicating the full shot noise, namely, the shot noise in the Schottky limit, both in the parallel and antiparallel magnetization configurations. This means the Poissonian process of the electron tunneling and the absence of the electron-electron correlation in the low bias regime. The shot noise measurements will be a good guideline to make up tunneling criteria for designing MTJ-based spin devices.