Electron transport in multiterminal molecular devices: A density functional theory study

Saha, Kamal Krishna; Lu, Wenchang; Bernholc, J.; Meunier, Vincent

doi:10.1103/physrevb.81.125420

Cited by 12 publications

(12 citation statements)

References 42 publications

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“…We also provide an overview of essential computational issues that have to be tackled when extending NEGF-DFT framework to nanojunctions containing more that two electrodes [30,31,32,33].…”

Section: Discussionmentioning

confidence: 99%

“…Our MT-NEGF-DFT code [30,31,32,33], implementing equations discussed in Sec. 3.2, utilizes ultrasoft pseudopotentials and PBE [50] parametrization of GGA for the XC functional of DFT.…”

Section: Negf-dft Methodology For Multiterminal Devicesmentioning

confidence: 99%

“…Here we overview the recent extension [30,31,32,33] of NEGF-DFT framework to treat nanojunctions whose active region is attached to more than two electrodes, and then apply it to GNR-CNT crossbars illustrated in Fig. 1.…”

mentioning

confidence: 99%

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Negative differential resistance in graphene-nanoribbon–carbon-nanotube crossbars: a first-principles multiterminal quantum transport study

Saha

Nikolić

2013

J Comput Electron

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We simulate quantum transport between a graphene nanoribbon (GNR) and a single-walled carbon nanotube (CNT) where electrons traverse vacuum gap between them. The GNR covers CNT over a nanoscale region while their relative rotation is 90 • , thereby forming a four-terminal crossbar where the bias voltage is applied between CNT and GNR terminals. The CNT and GNR are chosen as either semiconducting (s) or metallic (m) based on whether their two-terminal conductance exhibits a gap as a function of the Fermi energy or not, respectively. We find nonlinear current-voltage (I-V) characteristics in all three investigated devices-mGNR-sCNT, sGNR-sCNT and mGNR-mCNT crossbars-which are asymmetric with respect to changing the bias voltage from positive to negative. Furthermore, the I-V characteristics of mGNR-sCNT crossbar exhibits negative differential resistance (NDR) with low onset voltage V NDR 0.25 V and peak-to-valley current ratio 2.0. The overlap region of the crossbars contains only 460 carbon and hydrogen atoms which paves the way for nanoelectronic devices ultrascaled well below the smallest horizontal length scale envisioned by the international technology roadmap for semiconductors. Our analysis is based on the nonequilibrium Green function formalism combined with density functional theory (NEGF-DFT), where we also provide an overview of recent extensions of NEGF-DFT framework (originally developed for two-terminal devices) to multiterminal devices.

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“…We also provide an overview of essential computational issues that have to be tackled when extending NEGF-DFT framework to nanojunctions containing more that two electrodes [30,31,32,33].…”

Section: Discussionmentioning

confidence: 99%

“…Our MT-NEGF-DFT code [30,31,32,33], implementing equations discussed in Sec. 3.2, utilizes ultrasoft pseudopotentials and PBE [50] parametrization of GGA for the XC functional of DFT.…”

Section: Negf-dft Methodology For Multiterminal Devicesmentioning

confidence: 99%

See 1 more Smart Citation

Negative differential resistance in graphene-nanoribbon–carbon-nanotube crossbars: a first-principles multiterminal quantum transport study

Saha

Nikolić

2013

J Comput Electron

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“…Electron transmission in multiterminal molecular devices remains thus far a poorly explored area. Recent studies of coherent current in three‐ and four‐terminal systems 3–7 (and references therein) are based on Datta's trace formula 8 …”

mentioning

confidence: 99%

Coherent transmission in multiterminal molecular conductors

Malysheva

Onipko

2011

Physica Status Solidi (b)

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We consider coherent transport in an arbitrary molecular complex functioning as ${\cal N}$‐terminal conductor. The matrices that enter Datta's trace formula for the transmission function T(E) are represented in terms of free‐molecule Green's function matrix elements referring exclusively to molecular atoms perturbed by the lead–molecule interaction. Explicit expressions of transmission function are obtained for a commonly used model of multiterminal molecular devices, where the molecule is coupled with each lead via a single bond. In the particular cases of connection of molecular wires via a single atom and a benzene ring, this gives the analytical expressions of T(E). Physical implications of the derived formulas are briefly discussed.

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“…The first multi-terminal calculations used tight binding Hamiltonians 21,[29][30][31] and only a few first-principles calculations exist 23,27 . These calculations use the NEGF formalism extended to the three-and four-terminal case.…”

Section: Introductionmentioning

confidence: 99%

Calculation of electron transport in multiterminal systems using complex absorbing potentials

2011

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A method to calculate the transmission coefficient in multi-terminal systems is presented. By adding a complex absorbing potential to the Hamiltonian of the semi-infinite leads, the problem of inverting an infinite dimensional matrix is transformed into a finite dimensional eigenvalue problem. Using this approach transmission coefficients are calculated for all energies at once. The accuracy of the approach is demonstrated with an analytically solvable model system. Numerical examples of a four-terminal graphene cross junction and six-terminal carbon nanotube junction are presented.2

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Electron transport in multiterminal molecular devices: A density functional theory study

Cited by 12 publications

References 42 publications

Negative differential resistance in graphene-nanoribbon–carbon-nanotube crossbars: a first-principles multiterminal quantum transport study

Negative differential resistance in graphene-nanoribbon–carbon-nanotube crossbars: a first-principles multiterminal quantum transport study

Coherent transmission in multiterminal molecular conductors

Calculation of electron transport in multiterminal systems using complex absorbing potentials

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