Electronic structures of chiral carbon toroids

Lin, Ming–Fa; Chen, Rongbin; Shyu, Feng–Lin

doi:10.1016/s0038-1098(98)00191-4

Cited by 25 publications

(15 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…20͒, with Cϭ 2 /8 for zigzag tubes. 58 At the same time this deviation is much larger for other nanotube lines, even for the closest ones to the ''metallic'' line. For instance, the deviation of w ϩ,l Ј , lЈϭn/3Ϫ1, from unity is ͱ3/n.…”

Section: Transmission In the Gap Regionmentioning

confidence: 95%

Electron transmission through atom-contacted carbon nanotubes

2003

View full text Add to dashboard Cite

The transmission through side-contacted single-wall carbon nanotubes is investigated within the Landauer-Bütikker formalism for arbitrary tubes, geometries of contacts, and energies of transmission ͑E͒ for the case of monoatomic contacts. An efficient method to calculate transmission within the tight-binding approach including curvature effects is devised allowing, in particular, for an analytical treatment of zigzag, armchair, and some chiral tubes. The transmission function is described as a superposition of the contributions from onedimensional bands of all nanotube lines, each of them oscillating or/and decaying with the distance between the leads. We find five different types of antiresonances. Two of them arise from a destructive interference of the contributions from different nanotube lines when E is in the gap of semiconducting nanotubes and either are due to symmetry reasons or are accidental. A further two can show up at energies of Van Hove singularities originating from isolated singular points in 1D bands of nanotubes and can lead either to split or completely missing transmission peaks. The fifth one is related to the flat band in zigzag nanotubes at the energy of Van Hove singularity in graphene and results in zero transmission between carbon atoms belonging to different translational units in these tubes. A strong anisotropy of transmission in two opposite directions along the tube's axis is found in the middle of the energy gap of semiconducting nanotubes, which reaches several orders of magnitude in zigzag tubes. The transmission at Van Hove singularities ͑when nonzero͒ is of the order of unity and decays at a large axial distance R between the leads as R Ϫ2 , similarly to monoatomic chains. The transmission in the band region of nanotubes shows two types of behavior depending on the divisibility by three of the difference between corresponding reduced nanotube indices nЈϪmЈ. Close to the Fermi level the amplitude of the transmission function is independent from the chiral angle of the nanotubes and scales as an inverse square of their diameter.

show abstract

Section: Transmission In the Gap Regionmentioning

confidence: 95%

Electron transmission through atom-contacted carbon nanotubes

2003

View full text Add to dashboard Cite

show abstract

“…A CT is a rolled-up graphite sheet such that the carbon atom at the origin coincides with the two atoms at R x = ma 1 + na 2 and R y = pa 1 + qa 2 simultaneously (details in Fig. 1 of [26]), where a 1 and a 2 are the primitive lattice vectors of the graphite sheet. The parameters (m, n, p, q) define a carbon toroid.…”

Section: Theorymentioning

confidence: 99%

“…This new quasi-zero-dimensional system has motivated a lot of studies on geometric structures [18][19][20][21][22][23][24][25], electronic structures [26][27][28][29][30], magnetic properties [31][32][33][34][35][36], optical properties [37,38], electronic excitations [39,40], thermal properties [41], and transport properties [42,43]. One of their most interesting properties is that their electronic structures depend on the toroid geometry, such as radius, height, and chiral angle (h).…”

Section: Introductionmentioning

confidence: 99%

Magnetoelectronic states of carbon toroids

Shyu¹,

Tsai²,

Chang³

et al. 2004

Carbon

View full text Add to dashboard Cite

“…In addition to the well understood large diamagnetic response that scales with ring area, 8,9 a purely ''toroidal'' property, the anapole magnetic moment, is predicted. 11 Aharonov-Bohm oscillations of electronic structure 12 and persistent currents 13 in toroidal carbon nanotubes have also been investigated theoretically.…”

Section: Introductionmentioning

confidence: 99%

“…Later investigations, employing the concept of reciprocal space, were limited to tori from untwisted nanotubes containing an integer number of translational units. 9,12 However, the nanotubes in a rope are often observed to be twisted. ͓To avoid confusion in the case when nanotubes have intrinsic chirality ͑as do all tubes apart from the special ''armchair'' and ''zigzag'' classes͒, 14 note that ''twist'' here means an additional physical distortion caused by external forces.͔ Such twists have important topological consequences for toroidal nanotubes since the process of construction can ͑and sometimes must͒ introduce an offset at the place where the two ends meet.…”

Section: Introductionmentioning

confidence: 99%

The electronic structure of polyhex carbon tori

Ceulemans

Chibotaru

Bovin

et al. 2000

The Journal of Chemical Physics

View full text Add to dashboard Cite

The-orbital electronic structure of polyhex carbon tori constructed from bent individual single-wall nanotubes is investigated within the tight-binding approach. Analytical solutions for tori from nanotubes of arbitrary radius, length, chirality, and twisting angle are derived using simple geometrical and band-structure arguments. Vanishing of the gap between highest occupied and lowest unoccupied molecular orbitals for a torus imposes divisibility by 3 on the indices of chiral and twisting vectors, which translates into one graph-theoretical condition: a metallic polyhex torus is constructible as a leapfrog transformation of a smaller polyhex torus.

show abstract

Electronic structures of chiral carbon toroids

Cited by 25 publications

References 13 publications

Electron transmission through atom-contacted carbon nanotubes

Electron transmission through atom-contacted carbon nanotubes

Magnetoelectronic states of carbon toroids

The electronic structure of polyhex carbon tori

Contact Info

Product

Resources

About