Artículos de revistas
Graphene In The Quantum Hall Regime: Effects Of Vacancies, Sublattice Polarization And Disorder
Registro en:
International Journal Of Modern Physics B. , v. 23, n. Dez/13, p. 2618 - 2627, 2009.
2179792
2-s2.0-68249101356
Autor
Pereira A.L.C.
Schulz P.A.
Institución
Resumen
We investigate the effects of vacancies, disorder and sublattice polarization on the electronic properties of a monolayer graphene in the quantum Hall regime. Energy spectra as a function of magnetic field and the localization properties of the states within the graphene Landau levels (LLs) are calculated through a tight-binding model. We first discuss our results considering vacancies in the lattice, where we show that vacancies introduce extra levels (or well-defined bands) between consecutive LLs. An striking consequence here is that extra Hall resistance plateaus are expected to emerge when an organized vacancy superlattice is considered. Secondly, we discuss the anomalous localization properties we have found for the lowest LL, where an increasing disorder is shown to enhance the wave functions delocalization (instead of inducing localization). This unexpected effect is shown to be directly related to the way disorder increasingly destroys the sublattice (valley) polarization of the states in the lowest LL. The reason why this anomalous disorder effect occurs only for the zero-energy LL is that, in absence of disorder, only for this level all the states are sublattice polarized, i.e., their wave functions have amplitudes in only one of the sublattices. © 2009 World Scientific Publishing Company. 23 Dez/13 2618 2627 Novoselov, K.S., Geim, A.K., Morozov, S.V., Jiang, D., Katsnelson, M.I., Grig-orieva, I.V., Dubonos, S.V., Firsov, A.A., (2005) Nature, 438, p. 197 Zhang, Y., Tan, Y.-W., Stormer, H.L., Kim, P., (2005) Nature, 438, p. 201 Zhang, Y., Jiang, Z., Small, J.P., Purewal, M.S., Tan, Y.-W., Fazlollahi, M., Chu-dow, J.D., Kim, P., (2006) Phys. Rev. Lett, 96, p. 136806 Fuchs, J.N., Lederer, P., (2007) Phys. Rev. Lett, 98, p. 016803 Abanin, D.A., Lee, P.A., Levitov, L.S., (2007) Phys. Rev. Lett, 98, p. 156801 Koshino, M., Ando, T., (2007) Phys. Rev. B, 75, p. 033412 McCann, E., Kechedzhi, K., Fal'ko, V.I., Suzuura, H., Ando, T., Altshuler, B.L., (2006) Phys. Rev. Lett, 97, p. 146805 Sheng, L., Sheng, D.N., Haldane, F.D.M., Balents, L., (2007) Phys. Rev. Lett, 99, p. 196802 Apalkov, V.M., Chakraborty, T., (2006) Phys. Rev. Lett, 97, p. 126801 Rycerz, A., Tworzydlo, J., Beenakker, C.W.J., (2007) Nat. Phys, 3, p. 172 Pereira, A.L.C., Schulz, P.A., (2008) Phys. Rev. B, 77, p. 075416 Pereira, A.L.C., Schulz, P.A., (2008) Phys. Rev. B, 78, p. 125402 Thouless, D.J., Phys (1974) Reports, 13. , 93 Pereira, V.M., Guinea, F., Lopes dos Santos, J.M.B., Peres, N.M.R., Castro Neto, A.H., (2006) Phys. Rev. Lett, 96, p. 036801 Pereira, V.M., Lopes dos Santos, J.M.B., Castro Neto, A.H., (2008) Phys. Rev. B, 77, p. 115109 Palacios, J.J., Fernández-Rossier, J., Brey, L., (2008) Phys. Rev. B, 77, p. 195428 N. M. R. Peres, F. Guinea and A. H. Castro Neto, Phys. Rev. B 73, 125411 (2006)Geim, A.K., Novoselov, K.S., (2007) Nat. Mater, 6, p. 183 Tapasztó, L., Dobrik, G., Lambin, P., Biró, L.P., (2008) Nature Nanotech, 3, p. 397 Giesbers, A.J.M., Zeitlera, U., Neubeck, S., Freitag, F., Novoselov, K.S., Maan, J.C., (2008) Solid State Commun, 147, p. 366 Pereira, A.L.C., Schulz, P.A., (2002) Phys. Rev. B, 66, p. 155323