Theoretical studies of spin-dependent electronic transport in ferromagnetically contacted graphene flakes

Abstract

Based on a tight-binding model and a recursive Green's function technique, spin-depentent ballistic transport through tinny graphene sheets (flakes) is studied. The main interest is focussed on: electrical conductivity, giant magnetoresistance (GMR) and shot noise. It is shown that when graphene flakes are sandwiched between two ferromagnetic electrodes, the resulting GMR coefficient may be quite significant. This statement holds true both for zigzag and armchair chiralities, as well as for different aspect (width/length) ratios. Remarkably, in absolute values the GMR of the armchair-edge graphene flakes is systematically greater than that corresponding to the zigzag-edge graphene flakes. This finding is attributed to the different degree of conduction channel mixing for the two chiralities in question. It is also shown that for big aspect ratio flakes, 3-dimensional end-contacted leads, very much like invasive contacts, result in non-universal behavior of both conductivity and Fano factor.

to appear in PRB

References in corpus (23)

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• Electric-field controlled spin reversal in a quantum dot with ferromagnetic contacts
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• Electronic transport in normal-conductor/graphene/normal-conductor junctions and conditions for insulating behavior at a finite charge-carrier density
• Effect of contact induced states on minimum conductivity in graphene
• MagnetoResistance of graphene-based spin valves
• Magnetotransport through graphene spin valves
• Transport through single-wall metallic carbon nanotubes in the cotunneling regime
• Shot Noise Probing of Magnetic Ordering in Zigzag Graphene Nanoribbons
• Theoretical studies of spin-dependent electrical transport through carbon nanotbes
• Modeling a Schottky-barrier carbon nanotube field-effect transistor with ferromagnetic contacts

Cited by in corpus (10)

• Spin Transport and Relaxation in Graphene
• Graphene spintronics: the role of ferromagnetic electrodes
• Graphene nanoflakes in external electric and magnetic in-plane fields
• The RKKY Coupling between Impurity Spins in Graphene Nanoflakes
• Manifestation of the shape and edge effects in spin-resolved transport through graphene quantum dots
• Effect of the attachment of ferromagnetic contacts on the conductivity and giant magnetoresistance of graphene nanoribbons
• Spin-dependent transport for armchair-edge graphene nanoribbons between ferromagnetic leads
• Selected graphenelike zigzag nanoribbons with chemically functionalized edges: Implications for electronic and magnetic properties
• Magneto-transport in impurity-doped few-layer graphene spin valve
• Limited robustness of edge magnetism in zigzag graphene nanoribbons with electrodes