Transport properties of mesoscopic graphene rings

• Published in: Physica. B, Condensed matter Vol. 407; no. 3; pp. 335 - 339
• Main Authors: Xu, N., Ding, J.W., Wang, B.L., Shi, D.N., Sun, H.Q.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.02.2012; Elsevier
• Subjects: Computer simulation; Condensed matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductance; Disorders; Electric potential; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport; Electronic transport in mesoscopic systems; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Graphene; Graphene rings; Oscillations; Physics; Recursive functions; Graphene rings; Electronic transport; Rectification; Magnetic flux; Negative differential conductivity; Electrical conductivity; Aharonov-Bohm effect; Oscillations; Ballistic transport; Disorder; Tight binding approximation; Graphene; Rings; Transport processes; Green's function methods; Mesoscopic systems; IV characteristic
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2011.10.049

Based on a recursive Green's function method, we investigate the conductance of mesoscopic graphene rings in the presence of disorder, in the limit of phase coherent transport. Two models of disorder are considered: edge disorder and surface disorder. Our simulations show that the conductance decreases exponentially with the edge disorder and the surface disorder. In the presence of flux, a clear Aharonov–Bohm conductance oscillation with the period Φ 0 ( Φ 0= h/ e) is observed. The edge disorder and the surface disorder have no effect on the period of AB oscillation. The amplitudes of AB oscillations vary with gate voltage and flux, which is consistent with the previous results. Additionally, ballistic rectification and negative differential resistance are observed in I– V curves, with on/off characteristic.