Manifestation of the shape and edge effects in spin-resolved transport through graphene quantum dots

Abstract

We report on theoretical studies of transport through graphene quantum dots weakly coupled to external ferromagnetic leads. The calculations are performed by exact diagonalization of a tight-binding Hamiltonian with finite Coulomb correlations for graphene sheet and by using the real-time diagrammatic technique in the sequential and cotunneling regimes. The emphasis is put on the role of graphene flake shape and spontaneous edge magnetization in transport characteristics, such as the differential conductance, tunneling magnetoresistance (TMR) and the shot noise. It is shown that for certain shapes of the graphene dots a negative differential conductance and nontrivial behavior of the TMR effect can occur.

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Cited by in corpus (9)

• Graphene nanoflakes in external electric and magnetic in-plane fields
• Transport through graphene-like flakes with intrinsic spin orbit interactions
• Ground-state magnetic phase diagram of bow-tie graphene nanoflakes in external magnetic field
• Electrons trapped in graphene magnetic quantum dots with mass term
• Electric field control of the indirect magnetic coupling through a short graphene nanoribbon
• Limited robustness of edge magnetism in zigzag graphene nanoribbons with electrodes
• Conditional spin counting statistics as a probe of Coulomb interaction and spin-resolved bunching
• Magnetic, charge, and transport properties of graphene nanoflakes
• Magnetoelectric torque and edge currents in spin-orbit coupled graphene nanoribbons