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Related papers: Bandgaps of bent and buckled carbon nanotubes

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The importance of finite-size effects for the electronic structure of long zigzag and armchair carbon nanotubes is studied. We analyze the electronic structure of capped (6,6), (8,0), and (9,0) single walled carbon nanotubes as a function…

Chemical Physics · Physics 2007-05-23 Oded Hod , Juan E. Peralta , Gustavo E. Scuseria

We present a tight binding theory to analyze the motion of electrons between carbon nanotubes bundled into a carbon nanotube rope. The theory is developed starting from a description of the propagating Bloch waves on ideal tubes, and the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Ahmed A. Maarouf , Charles L. Kane , Eugene J. Mele

The band structures of the periodic nanotube junctions are investigated by the effective mass theory and the tight binding model. The periodic junctions are constructed by introducing pairs of a pentagonal defect and a heptagonal defect…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Ryo Tamura , Masaru Tsukada

One of severe limits of graphene nanoribbons (GNRs) in future applications is that zigzag GNRs (ZGNRs) are gapless, so cannot be used in field effect transistors (FETs). In this paper, using tight-binding approach and first principles…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 Aihua Zhang , Yihong Wu , San-Huang Ke , Yuan Ping Feng , Chun Zhang

We numerically study the statistical fluctuations of photonic band gaps in ensembles of stealthy hyperuniform disordered patterns. We find that at low stealthiness, where correlations are weak, band gaps of different system realizations…

Classical Physics · Physics 2023-05-31 Luis S. Froufe-Pérez , Geoffroy Aubry , Frank Scheffold , Sofia Magkiriadou

Using the Landauer-Buttiker formalism, we calculate the effect of structural twist on electron transport in conducting carbon nanotubes. We demonstrate that even a localized region of twist scatters the propagating pi electrons and induces…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Steven W. D. Bailey , David Tomanek , Young-Kyun Kwon , Colin J. Lambert

Using large-scale DFT calculations (up to 1,476 atoms and 18,432 orbitals), we present the first detailed analysis on the unusual electronic properties of recently synthesized porphyrin nanotubes. We surprisingly observe extremely large…

Mesoscale and Nanoscale Physics · Physics 2018-03-07 Sarah I. Allec , Niranjan V. Ilawe , Bryan M. Wong

The validity of the DFT models implemented by FIREBALL for CNT electronic device modeling is assessed. The effective masses, band gaps, and transmission coefficients of semi-conducting, zigzag, (n,0) carbon nanotubes (CNTs) resulting from…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Deep Shah , Nicolas A. Bruque , Khairul Alam , Roger K. Lake , Rajeev R. Pandey

We investigate curvature effects on geometric parameters, energetics and electronic structure of zigzag nanotubes with fully optimized geometries from first-principle calculations. The calculated curvature energies, which are inversely…

Materials Science · Physics 2009-11-07 O. Gulseren , T. Yildirim , S. Ciraci

We investigate the electronic instabilities in carbon nanotubes of short radius, looking for the breakdown of the Luttinger liquid regime from the singular behavior of the charge stiffnesses at low energies. We show that such a breakdown is…

Strongly Correlated Electrons · Physics 2009-11-10 J. Gonzalez

Bandgaps in layered materials are critical for enabling functionalities such as tunable photodetection, efficient energy conversion, and nonlinear optical responses, which are essential for next-generation photonic and quantum devices. Gap…

Deformations of single-wall carbon nanotubes are investigated within the tight-binding model with deformation-dependent hopping energies. We show that the nanotubes tend to twist and shrink spontaneously at zero temperature. The explicit…

Mesoscale and Nanoscale Physics · Physics 2017-07-05 Vít Jakubský , Axel Pérez-Obiol

The present paper investigates the cross-sectional morphology of Multiwalled Carbon Nanotubes (MWNTs) restrained radially and circumferentially by an infinite surrounding elastic medium, subjected to uniform external hydrostatic pressure.…

Materials Science · Physics 2015-05-13 Motohiro Sato , Hiroyuki Shima , Kohtaroh Iiboshi

Band gap modification for small-diameter (1 nm) silicon nanowires resulting from the use of different species for surface termination is investigated by density functional theory calculations. Because of quantum confinement, small-diameter…

Materials Science · Physics 2010-02-03 Michael Nolan , Sean O'Callaghan , Giorgos Fagas , James C. Greer , Thomas Frauenheim

We have investigated the magnetoconductance of semiconducting carbon nanotubes (CNTs) in pulsed, parallel magnetic fields up to 60 T, and report the direct observation of the predicted band-gap closure and the reopening of the gap under…

Mesoscale and Nanoscale Physics · Physics 2011-03-08 S. H. Jhang , M. Marganska , Y. Skourski , D. Preusche , M. Grifoni , J. Wosnitza , C. Strunk

The ability to control wave propagation is of fundamental interest in many areas of physics. Photonic and phononic crystals have proved very useful for this purpose but, because they are based on Bragg interference, these artificial media…

Analysis of PDEs · Mathematics 2020-09-15 Habib Ammari , Brian Fitzpatrick , Erik Orvehed Hiltunen , Sanghyeon Yu

We use the robust nearest-neighbour tight-binding approximation to study on the same footing interband dipole transitions in narrow-bandgap carbon nanotubes and graphene nanoribbons. It is demonstrated that curvature effects in metallic…

Mesoscale and Nanoscale Physics · Physics 2019-04-30 R. R. Hartmann , V. A. Saroka , M. E. Portnoi

Interfacial friction plays a crucial role in the mechanical properties of carbon nanotube based fibers, composites, and devices. Here we use molecular dynamics simulation to investigate the pressure effect on the friction within carbon…

Materials Science · Physics 2010-01-27 Xiaohua Zhang , Qingwen Li

Structure of the spin-orbit coupling varies from material to material and thus finding the correct spin-orbit coupling structure is an important step towards advanced spintronic applications. We show theoretically that the curvature in a…

Mesoscale and Nanoscale Physics · Physics 2011-09-14 Jae-Seung Jeong , Hyun-Woo Lee

We show, using ab initio total energy density functional theory, that the so-called Wigner defects, an interstitial carbon atom right besides a vacancy, which are present in irradiated graphite can also exist in bundles of carbon nanotubes.…

Materials Science · Physics 2015-06-24 Antonio J. R. da Silva , A. Fazzio , Alex Antonelli