The transmission probability against the electron normal incident energy through an asymmetrical two-magnetic-barrier structure of single layer graphene has been investigated and presented. One barrier's height and width are varied while those of the other are kept at constant values. The effect of the structural asymmetry on the resonance energy and the resonant transmission peak value are also systematically studied with the help of numerical calculations based on the transfer matrix method. Investigations show that the unity transmission occurs in an asymmetrical two-magnetic-barrier structure when both the phase difference condition for resonance (PDCR) and the maximum condition for the resonance peak value (MCPV) are satisfied simultaneously. However, PDCR underestimates the resonance energy of an asymmetrical two-magnetic-barrier structure, and the deviation becomes more obvious as the structure progressively becomes less symmetrical. These findings are believed to be of significant importance for the design of single layer graphene based devices.

Resonant tunneling; Asymmetrical two-magnetic barriers; Resonance energy

Beihang University; The University of Nottingham-Ningbo