Large-scale tight-binding simulations of quantum transport in ballistic graphene: Paper

Research output: Contribution to journalJournal article – Annual report year: 2018Researchpeer-review

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Large-scale tight-binding simulations of quantum transport in ballistic graphene : Paper. / Calogero, Gaetano; Papior, Nick Rübner; Bøggild, Peter; Brandbyge, Mads.

In: JOURNAL OF PHYSICS-CONDENSED MATTER, Vol. 30, No. 36, 2018.

Research output: Contribution to journalJournal article – Annual report year: 2018Researchpeer-review

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@article{879570ef08f1431c814bfbc8d61932a5,
title = "Large-scale tight-binding simulations of quantum transport in ballistic graphene: Paper",
abstract = "Graphene has proven to host outstanding mesoscopic effects involving massless Dirac quasiparticles travelling ballistically resulting in the current flow exhibiting light-like behaviour. A new branch of 2D electronics inspired by the standard principles of optics is rapidly evolving, calling for a deeper understanding of transport in large-scale devices at a quantum level. Here we perform large-scale quantum transport calculations based on a tight- binding model of graphene and the non-equilibrium Green's function method and include the effects of p-n junctions of different shape, magnetic field, and absorptive regions acting as drains for current. We stress the importance of choosing absorbing boundary conditions in the calculations to correctly capture how current flows in the limit of infinite devices. As a specific application we present a fully quantum-mechanical framework for the '2D Dirac fermion microscope' recently proposed by Boggild et al (2017 Nat. Commun. 8 10.1038), tackling several key electron-optical effects therein predicted via semiclassical trajectory simulations, such as electron beam collimation, deflection and scattering off Veselago dots. Our results confirm that a semiclassical approach to a large extend is sufficient to capture the main transport features in the mesoscopic limit and the optical regime, but also that a richer electron-optical landscape is to be expected when coherence or other purely quantum effects are accounted for in the simulations.",
keywords = "Graphene, NEGF, Large-scale, Tight-binding, Quantum transport, Dirac fermion microscope",
author = "Gaetano Calogero and Papior, {Nick R{\"u}bner} and Peter B{\o}ggild and Mads Brandbyge",
year = "2018",
doi = "10.1088/1361-648X/aad6f1",
language = "English",
volume = "30",
journal = "Journal of Physics: Condensed Matter",
issn = "0953-8984",
publisher = "IOP Publishing",
number = "36",

}

RIS

TY - JOUR

T1 - Large-scale tight-binding simulations of quantum transport in ballistic graphene

T2 - Paper

AU - Calogero, Gaetano

AU - Papior, Nick Rübner

AU - Bøggild, Peter

AU - Brandbyge, Mads

PY - 2018

Y1 - 2018

N2 - Graphene has proven to host outstanding mesoscopic effects involving massless Dirac quasiparticles travelling ballistically resulting in the current flow exhibiting light-like behaviour. A new branch of 2D electronics inspired by the standard principles of optics is rapidly evolving, calling for a deeper understanding of transport in large-scale devices at a quantum level. Here we perform large-scale quantum transport calculations based on a tight- binding model of graphene and the non-equilibrium Green's function method and include the effects of p-n junctions of different shape, magnetic field, and absorptive regions acting as drains for current. We stress the importance of choosing absorbing boundary conditions in the calculations to correctly capture how current flows in the limit of infinite devices. As a specific application we present a fully quantum-mechanical framework for the '2D Dirac fermion microscope' recently proposed by Boggild et al (2017 Nat. Commun. 8 10.1038), tackling several key electron-optical effects therein predicted via semiclassical trajectory simulations, such as electron beam collimation, deflection and scattering off Veselago dots. Our results confirm that a semiclassical approach to a large extend is sufficient to capture the main transport features in the mesoscopic limit and the optical regime, but also that a richer electron-optical landscape is to be expected when coherence or other purely quantum effects are accounted for in the simulations.

AB - Graphene has proven to host outstanding mesoscopic effects involving massless Dirac quasiparticles travelling ballistically resulting in the current flow exhibiting light-like behaviour. A new branch of 2D electronics inspired by the standard principles of optics is rapidly evolving, calling for a deeper understanding of transport in large-scale devices at a quantum level. Here we perform large-scale quantum transport calculations based on a tight- binding model of graphene and the non-equilibrium Green's function method and include the effects of p-n junctions of different shape, magnetic field, and absorptive regions acting as drains for current. We stress the importance of choosing absorbing boundary conditions in the calculations to correctly capture how current flows in the limit of infinite devices. As a specific application we present a fully quantum-mechanical framework for the '2D Dirac fermion microscope' recently proposed by Boggild et al (2017 Nat. Commun. 8 10.1038), tackling several key electron-optical effects therein predicted via semiclassical trajectory simulations, such as electron beam collimation, deflection and scattering off Veselago dots. Our results confirm that a semiclassical approach to a large extend is sufficient to capture the main transport features in the mesoscopic limit and the optical regime, but also that a richer electron-optical landscape is to be expected when coherence or other purely quantum effects are accounted for in the simulations.

KW - Graphene

KW - NEGF

KW - Large-scale

KW - Tight-binding

KW - Quantum transport

KW - Dirac fermion microscope

U2 - 10.1088/1361-648X/aad6f1

DO - 10.1088/1361-648X/aad6f1

M3 - Journal article

VL - 30

JO - Journal of Physics: Condensed Matter

JF - Journal of Physics: Condensed Matter

SN - 0953-8984

IS - 36

ER -