Article

Gate tunable non-linear currents in bilayer graphene diodes

Applied Physics Letters (Impact Factor: 3.52). 01/2012; 100(3). DOI: 10.1063/1.3676441
Source: arXiv

ABSTRACT Electric transport of double gated bilayer graphene devices is studied as a
function of charge density and bandgap. A top gate electrode can be used to
control locally the Fermi level to create a pn junction between the
double-gated and single-gated region. These bilayer graphene pn diodes are
characterized by non-linear currents and directional current rectification, and
we show the rectified direction of the source-drain voltage can be controlled
by using gate voltages. A systematic study of the pn junction characteristics
allows to extract a gate-dependent bandgap value which ranges from 0 meV to 130
meV.

0 Bookmarks
 · 
110 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Conducting steady-states of doped bilayer graphene have a non-zero sublattice pseudospin polarization. Electron-electron interactions renormalize this polarization even at zero temperature, when the phase space for electron-electron scattering vanishes. We show that because of the strength of interlayer tunneling, electron-electron interactions nevertheless have a negligible influence on the conductivity which vanishes as the carrier number density goes to zero. The influence of interactions is qualitatively weaker than in the comparable cases of single-layer graphene or topological insulators, because the momentum-space layer pseudospin vorticity is 2 rather than 1. Our study relies on the quantum Liouville equation in the first Born approximation with respect to the scattering potential, with electron-electron interactions taken into account self-consistently in the Hartree-Fock approximation and screening in the random phase approximation. Within this framework the result we obtain is exact.
    Phys. Rev. B 87. 12/2013;
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigate the electronic structure of graphene ribbons under the competition between lateral electric and normal magnetic fields. The squeezing of quantum level spacings caused by either field is studied. Based on the knowledge of the dispersion under both fields, we analyze the electronic trajectories near the junctions of different electric and magnetic fields configurations. The junctions can split and join electron beams, and the conductance is quite robust against disorder near the junction interfaces. These junction devices can be used as bricks for building more complicated interference devices.
    Physics Letters A 03/2012; 376(14):1215–1218. · 1.63 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We propose using disorder to produce a field effect transistor (FET) in biased bilayer and trilayer graphene. Modulation of the bias voltage can produce large variations in the conductance when the effects of disorder are confined to only one of the graphene layers. This effect is based on the ability of the bias voltage to select which of the graphene layers carries current, and is not tied to the presence of a gap in the density of states. In particular, we demonstrate this effect in models of gapless ABA-stacked trilayer graphene, gapped ABC-stacked trilayer graphene and gapped bilayer graphene.
    Journal of Physics Condensed Matter 02/2013; 25(10):105303. · 2.22 Impact Factor

Full-text (2 Sources)

View
30 Downloads
Available from
May 20, 2014