Magnetoresistance and negative differential resistance in Ni/graphene/Ni vertical heterostructures driven by finite bias voltage: a first-principles study
Publication: Research - peer-review › Journal article – Annual report year: 2012
Using the nonequilibrium Green's function formalism combined with density functional theory, we study finite bias quantum transport in Ni/Grn/Ni vertical heterostructures where n graphene layers are sandwiched between two semi-infinite Ni(111) electrodes. We find that the recently predicted “pessimistic” magnetoresistance of 100% for n≥5 junctions at zero bias voltage Vb→0 persists up to Vb≃0.4 V, which makes such devices promising for spin-torque-based device applications. In addition, for parallel orientations of the Ni magnetizations, the n=5 junction exhibits a pronounced negative differential resistance as the bias voltage is increased from Vb=0 V to Vb≃0.5 V. We confirm that both of these nonequilibrium transport effects hold for different types of bonding of Gr on the Ni(111) surface while maintaining Bernal stacking between individual Gr layers.
|Journal||Physical Review B (Condensed Matter and Materials Physics)|
|State||Published - 2012|
©2012 American Physical Society
|Citations||Web of Science® Times Cited: 12|
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