Viet-Hung Nguyen, Yann-Michel Niquet, Philippe Dollfus
We report a numerical study on Aharonov-Bohm (AB) effect and giant magnetoresistance in rectangular rings made of graphene nanoribbons (GNRs). We show that in low energy regime where only the first subband of contact GNRs contributes to the transport, the transmission probability can be strongly modulated, i.e., almost fully suppressed, when tuning a perpendicular magnetic field. On this basis, strong AB oscillations with giant negative magnetoresistance can be achieved at room temperature. The magnetoresistance reaches up to a few ten thousand % in perfect GNR rings and about a few hundred % with edge disordered GNRs. The design rules to observe such strong effects are also discussed. Our study hence provides guideline for further investigations of the AB interference and puts forward the high magnetoresistance applications of graphene.
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http://arxiv.org/abs/1303.4946
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