Multiple States of Nanoring Magnetic Tunnel Junctions @ Johns Hopkins University

Background: The geometry of a nanoring magnet provides unique magnetic configurations of onion, vortex, and twisted, which can be exploited in nanoring magnetic tunnel junctions (NRMTJs) . When the reference layer is in the onion state, the storage layer in a NRMTJ can acquire the onion, the reversed onion, and the twisted state, where the first two by linear magnetic field, and the third by spin torque and a circulatory field. We have achieved these states in 100-nm nanoring MTJs, the smallest to date. Notice the low resistance states by either field switching or current switching are the same, whereas the high resistance states are different.

Related publication(s):

1. H. X. Wei, F. Q. Zhu, X. F. Han, Z. C. Wen, and C. L. Chien, Current-induced multiple spin structures in 100 nm ring magnetic tunnel junctions,àƒ’® Phys. Rev. B. 77, 224432 (2008).