Dynamic Conductance of Carbon Nanotubes

Roland, Christopher; Nardelli, Marco Buongiorno; Wang, Jian; Guo, Hong

doi:10.1103/physrevlett.84.2921

Cited by 69 publications

(55 citation statements)

References 57 publications

(57 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[7] In this paper, we focus on the ac conductance of finite-length CNTs because they are more practical for interconnecting nanoscale circuits and systems. The system we consider is a finite-length CNT between two electrodes, L and R, with ac signals applied to the electrodes.…”

Section: Introductionmentioning

confidence: 99%

AC conductance of finite-length carbon nanotubes

He¹,

Hou²,

Liu³

et al. 2006

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Abstract:We propose a nonequilibrium Green's function approach to calculate the ac conductance of various finite-length carbon nanotubes. The simulated ac conductance differs significantly from that of the infinite-length ones. At the low-frequency limit, the profiles of the quantized conductance are still observable in the finite-length carbon nanotubes, but many more peaks appear on the conductance curves. We also show that the conductance of finite-length carbon nanotubes will oscillate as a function of the ac frequency. The dependence of the oscillation on the lengths, helicities and defects of the carbon nanotubes are also investigated. The knowledge we gain from this research will help us make carbon-nanotube-based interconnects or other ac devices in the future.Carbon nanotubes (CNTs), since their discovery, have been considered as one of the most promising building blocks for future nanoelectronic devices.[1] Among various applications, the use of CNTs as interconnects is quite promising. [2][3][4] CNTs have several superior features compared to those of traditional metallic interconnection materials: (1) CNTs have good dc conductance due to their quasi-one-dimensional structures; [5,6] (2) No dangling bonds exist on the surface of CNTs; thus, their transport properties are not affected by the surface scattering or the surface roughness when the feature size of the interconnect shrinks; (3) C-C bonds within CNTs are one of the strongest bonds in nature, thus making CNTs chemically stable in the process flow. However, effective models are needed to quantitatively evaluate the transport properties of CNTs.Researchers have simulated ac transport in the infinite-length CNTs by using nonequilibrium Green's functions technique. [7] In this paper, we focus on the ac conductance of finite-length CNTs because they are more practical for interconnecting nanoscale circuits and systems. The system we consider is a finite-length CNT between two electrodes, L and R, with ac signals applied to the electrodes. We employ the tight-binding π-electron model for the CNT, and link its ac conductance to its Green's functions at steady-state. Usually, these Green's functions are calculated via direct matrix inverting from their definition. However, for finite-length CNTs such as a (10, 10) CNT about 13 nanometers, the dimension of the matrices to be inverted is about 4000. Not only will it be time-consuming but also it will be quite inaccurate to invert such large dimensional matrices. Here in this work we employ Recursive Green's function technique [8,9] to build up them. With this approach, the dimension of matrices to be inverted is determined by the helicity of the CNT but not the length. That is, it will only involve 20-dimensional matrix inversion for (10, 10) CNT. Besides, in the recursive approach only a few elements which are concerned need to be calculated, while in the direct matrix inverting approach every element of the CNT's Green's functions must be calculated. Hence this recursive approach will obviously relax ...

show abstract

Section: Introductionmentioning

confidence: 99%

AC conductance of finite-length carbon nanotubes

He¹,

Hou²,

Liu³

et al. 2006

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…On the numerical side, finite frequency physics has attracted comparatively limited interest so far. Pioneer works include some calculations by Guo et al [65][66][67][68] as well as a few others 48,[69][70][71][72][73][74][75][76][77] .…”

Section: Introductionmentioning

confidence: 99%

Numerical toolkit for electronic quantum transport at finite frequency

Shevtsov

Waintal

2013

Phys. Rev. B

View full text Add to dashboard Cite

Building on the many existing algorithms for calculating the DC transport properties of quantum tight-binding models, we develop a systematic approach that expresses finite frequency observables in terms of the stationary Green's function of the system, i.e. the natural output of most DC numerical codes. Our framework allows to extend the simulations capabilities of existing codes to a large class of observables including, for instance, AC conductance, quantum capacitance, quantum pumping, spin pumping or photo-assisted shot noise. The theory is developed within the framework of Keldysh formalism and we provide explicit links with the alternative (and equivalent) scattering approach. We illustrate the formalism with a study of the AC conductance in a quantum point contact and an electronic Mach-Zehnder interferometer in the quantum Hall regime.

show abstract

“…Techniques for quantum transport simulation [1][2][3][4][5][6][7] are very important for the development of molecular electronics [8]. Many of these techniques are based on a non-equilibrium Green function (NEGF) approach [1,2], and electronic structure methods (ESM).…”

Section: Introductionmentioning

confidence: 99%

A self-consistent tight binding model for hydrocarbon systems: application to quantum transport simulation

Areshkin

Shenderova

Schall

et al. 2004

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

A self-consistent environment-dependent (SC-ED) tight binding (TB) method for hydrocarbons that was developed for quantum transport simulations is presented. The method builds on a non-self-consistent environment-dependent TB model for carbon (Tang et al 1996 Phys. Rev. B 53 979) with parameters added to describe hydrocarbon bonds and to account for self-consistent charge transfer. The SC-EDTB model assumes an orthogonal basis set. Orthogonality is a key element for adapting the SC-EDTB scheme to transport problems because it substantially increases the efficiency of the NewtonRaphson algorithm used to accelerate self-consistency convergence under nonequilibrium conditions. Compared to most existing TB schemes the SC-EDTB scheme is distinctive in two respects. First, self-consistency is added through the exact evaluation of Hartree and linear expansion of exchange integrals. All Hamiltonian elements belonging to the same atom are affected by charge transfer, not just the diagonal elements. The second distinction is the choice of SC-EDTB parameters; they were fitted to Mulliken populations and eigenvalue spectra rather than energies or elastic properties. The former are directly related to the conductivity and potential profile, which are essential for transport simulation. No two-centre repulsive term parametrization was performed. The functionality of the method is exemplified by computing I -V curves, nonequilibrium potential profiles and current density for a resonant tunnelling device.

show abstract

Dynamic Conductance of Carbon Nanotubes

Cited by 69 publications

References 57 publications

AC conductance of finite-length carbon nanotubes

AC conductance of finite-length carbon nanotubes

Numerical toolkit for electronic quantum transport at finite frequency

A self-consistent tight binding model for hydrocarbon systems: application to quantum transport simulation

Contact Info

Product

Resources

About