Conductance distribution in doped and defected graphene nanoribbons

Antonino La Magna, Ioannis Deretzis, Giuseppe Forte, and Renato Pucci

Phys. Rev. B 80, 195413 – Published 17 November 2009

Abstract

Electronic transport at the $μ m$ length scale is theoretically investigated for $N$ -doped and vacancy damaged graphene nanoribbons. In these systems, localization due to scattering is strongly energy dependent, and this fact leads to the appearance of conductance quasigaps in the spectral region of the resonance states. Conductance fluctuations are very large in the quasigap regions and increase linearly with the system size. The single parameters scaling hypothesis is not verified for energies in a zone including the charge neutrality point while it is valid for energies away from this zone.

Received 29 August 2009

DOI:https://doi.org/10.1103/PhysRevB.80.195413

Authors & Affiliations

Antonino La Magna

CNR–IMM, Z.I. VIII Strada 5, 95121 Catania, Italy

Ioannis Deretzis

Scuola Superiore, Università di Catania, I-95123 Catania, Italy and CNR–IMM, Z.I. VIII Strada 5, 95121 Catania, Italy

Giuseppe Forte

Dipartimento di Scienze Chimiche, Facoltà di Farmacia, Università di Catania, Viale A. Doria 6, I-95126 Catania, Italy

Renato Pucci

Dipartimento di Fisica e Astronomia, Università di Catania and CNISM, UdR di Catania, Via S. Sofia 64, I-95123 Catania, Italy

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Issue

Vol. 80, Iss. 19 — 15 November 2009

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Images

Figure 1
Average conductance $⟨ g ⟩$ (a) and conductance fluctuations $σ^{2}$ (b) as a function of the energy $E$ , for an N doped $N_{a} = 47 -AGNR$ of different lengths: $L = 500$ (dashes and dots), 1000 (solid lines), 2000 (dots), and 4000 (dashes). The lengths in $μ m$ are also reported. Plotted values represent statistical averages over more than 500 equivalent replicas of the system. Charge neutrality points of pure and doped systems are aligned at $E = 0$ in the figure.Reuse & Permissions
Figure 2
Average conductance $⟨ g ⟩$ (a) and conductance fluctuations $σ^{2}$ (b) as a function of the energy $E$ , for a $V$ -damaged $N_{a} = 47 AGNR$ of different lengths: $L = 500$ (dashes and dots), 1000 (solid lines), 2000 (dots), and 4000 (dashes). The lengths in $μ m$ are also reported. Plotted values represent statistical averages over more of 500 equivalent replicas of the system. Charge neutrality points of pure and defected systems are aligned at $E = 0$ in the figure.Reuse & Permissions
Figure 3
(Color online) Conductance fluctuations $σ^{2}$ as a function of the average of the conductance natural logarithm $⟨ ln (g) ⟩$ for different $N$ -doped $N_{a} = 45 AGNRs$ . Each point represents a statistical average over more of 500 equivalent replicas of the system. The systems differ for: scatter center density (0.2%, 0.4% cases), Fermi energy $E$ , which belongs to the interval $[- 1, 1]$ and length $L = 500, 1000, 1500, 2000, 4000$ . Red triangles evidence points for energies $E$ in the intervals $[- 1, - 0.5]$ and [0.5,1].Reuse & Permissions
Figure 4
(Color online) Conductance fluctuations $σ^{2}$ as a function of the average of the conductance natural logarithm $⟨ ln (g) ⟩$ for different $N$ -doped $N_{a} = 47 AGNRs$ . Each point represents a statistical average over more than 500 equivalent replicas of the system. The systems differs for: scatter centers density (0.1%, 0.2% 0.4% cases), Fermi energy $E$ , which belongs to the interval $[- 1, 1]$ and length $L = 500, 1000, 1500, 2000, 3000, 4000$ . Red triangles evidence points for energies $E$ in the intervals $[- 1, - 0.5]$ and [0.5,1].Reuse & Permissions
Figure 5
(Color online) Conductance fluctuations $σ^{2}$ as a function of the average of the conductance natural logarithm $⟨ ln (g) ⟩$ for different $V$ -damaged $N_{a} = 47 AGNRs$ . Each point represents a statistical average over more than 500 equivalent replica of the system. The systems differ for scatter centers density (0.2% 0.4% cases), Fermi energy $E$ , which belongs to the interval $[- 1, 1]$ , and length $L = 500, 1000, 2000, 4000$ . Red triangles evidence values for energies $E$ in the intervals $[- 1, - 0.5]$ and [0.5,1].Reuse & Permissions

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