Sub-Poissonian shot noise in CoFeB/MgO/CoFeB-based magnetic tunneling   junctions
  We measured the shot noise in the CoFeB/MgO/CoFeB-based magnetic tunneling junctions with a high tunneling magnetoresistance ratio (over 200% at 3 K). Although the Fano factor in the anti-parallel configuration is close to unity, it is observed to be typically 0.91\pm0.01 in the parallel configuration. It indicates the sub-Poissonian process of the electron tunneling in the parallel configuration due to the relevance of the spin-dependent coherent transport in the low bias regime. 
Tomonori Arakawa, Koji Sekiguchi, Shuji Nakamura, Kensaku Chida,   Yoshitaka Nishihara, Daichi Chiba, Kensuke Kobayashi, Aki...
cond-mat.mes-hall