Abstract
The advent of spin transfer torque effect accommodates site-specific switching of magnetic nanostructures by current alone without magnetic field. However, the critical current density required for usual spin torque switching remains stubbornly high around 106–107 A cm−2. It would be fundamentally transformative if an electric field through a voltage could assist or accomplish the switching of ferromagnets. Here we report electric-field-assisted reversible switching in CoFeB/MgO/CoFeB magnetic tunnel junctions with interfacial perpendicular magnetic anisotropy, where the coercivity, the magnetic configuration and the tunnelling magnetoresistance can be manipulated by voltage pulses associated with much smaller current densities. These results represent a crucial step towards ultralow energy switching in magnetic tunnel junctions, and open a new avenue for exploring other voltage-controlled spintronic devices.
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Acknowledgements
This work is supported by the National Science Foundation under grant No DMR05-20491.
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W-G.W. and C.L.C. conceived and designed the experiments. W-G.W. and M.L. fabricated the MTJ films and nanopillars. M.L., S.H. and W-G.W. measured transport and magnetic properties of the samples. C.L.C. supervised the study. W-G.W. and C.L.C. wrote the manuscript and all authors discussed the results and commented on the manuscript.
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Wang, WG., Li, M., Hageman, S. et al. Electric-field-assisted switching in magnetic tunnel junctions. Nature Mater 11, 64–68 (2012). https://doi.org/10.1038/nmat3171
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DOI: https://doi.org/10.1038/nmat3171
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