Polarized spin and valley transport across ferromagnetic silicene junctions
- Department of Physics, Concordia University, 7141 Sherbrooke Ouest Montréal, Québec H4B 1R6 (Canada)
We study ballistic transport of Dirac fermions through silicene barriers, of width d, with an exchange field M and metallic gates above them that provide tunable potentials of height U. Away from the Dirac point (DP), the spin- and valley-resolved conductances, as functions of U, exhibit resonances and close to it a pronounced dip that becomes a transport gap when an appropriate electric field E{sub z} is applied. The charge conductance g{sub c} of such a junction changes from oscillatory to a monotonically decreasing function of d beyond a critical E{sub z}. This change of g{sub c} can be used to realize electric-field-controlled switching. The field M splits each resonance of g{sub c} in two spin-resolved peaks. The spin p{sub s} and valley p{sub v} polarizations of the current near the DP increase with E{sub z} or M and become nearly perfect above certain of their values. We also show that p{sub s} and p{sub v} can be inverted either by reversing the polarity of U or the direction of M. For two barriers, there is no splitting in g{sub c} when the fields M are in opposite directions. Most of these phenomena have no analogs in graphene.
- OSTI ID:
- 22413216
- Journal Information:
- Journal of Applied Physics, Vol. 117, Issue 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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