100 likes | 296 Views
Power-Law Correlated Disorder in Graphene and Square Nanoribbons. Greg M. Petersen Nancy Sandler Ohio University Department of Physics and Astronomy. Disorder in Graphene. Real Disordered Materials Have Correlations. Scattering Mechanisms:. Neutral Absorbents. Neutral Absorbents.
E N D
Power-Law Correlated Disorder in Graphene and Square Nanoribbons Greg M. Petersen Nancy Sandler Ohio University Department of Physics and Astronomy
Disorder in Graphene Real Disordered Materials Have Correlations Scattering Mechanisms: Neutral Absorbents Neutral Absorbents Lijie Ci et al. Nature Mat. (2010) Ripples Strain/Shear Vacancies Topological defects Coulomb Impurities Greg M. Petersen
1D Anderson Transition? Evidence For Evidence Against Dunlap, Wu, and Phillips, PRL (1990) Abrahams et al. PRL (1979) Johnston and Kramer Z Phys. B (1986) Kotani and Simon, Commun. Math. Phys (1987) García-García and Cuevas, PRB (2009) Cain et al. EPL (2011) Shameless Advertisement:Section: Z16 Moura and Lyra, PRL (1998) Petersen and Sandler (To be submitted) Greg M. Petersen
Introducing Long-Range Disorder α=.1 uncorrelated α=.5 Generation Method: 1. Find spectral density 2. Generate { V(k) } from gaussian with variance S(k) 3. Apply conditions V(k) = V*(-k) 4. Take inverse FT to get { Єi } α=1 Greg M. Petersen
Recursive Green's Function Method Lead Conductor Lead Also get DOS Klimeck http://nanohub.org/resources/165 (2004) Greg M. Petersen
Square Ribbon W/t = 0.5 L = 27-211 All Localized Greg M. Petersen Greg M. Petersen
Zig-Zag Nanoribbons E~0 Zettl, et al. Science (2009) E~0 What role do long range-spatial correlations play?How are the edge states affected? Nakada, Fujita, PRB (1996) Mucciolo et al. PRB (2009) Greg M. Petersen
Zig-Zag Ribbon: Conductance W/t = 0.1 L = 26-212 Black: UC E/t = 0 E/t = 1 E/t = 2 Greg M. Petersen
Zig-Zag Ribbon W/t = 0.1 L = 212 ~14% change Black: UC /t /t Zarea and Sandler PRB (2009) ~50% change /t Greg M. Petersen
Conclusions - We confirm single parameter scaling of the beta function for square ribbons and zig-zag ribbons - The density of states at E=0 is dependent on geometry and disorder Cain et al. EPL (2011) – no transition Petersen, Sandler (2012) - no transition Moura and Lyra, PRL (1998) - transition - Long Range Correlations are Not Sufficient for Anderson Transition in 1D Thank you for your attention! Greg M. Petersen