Single-wall carbon nanotubes phonon spectra: Symmetry-based calculations

Dobardžić, E.; Milošević, I.; Nikolić, Božidar; Vuković, T.; Damnjanović, Milan

doi:10.1103/physrevb.68.045408

Cited by 106 publications

(116 citation statements)

References 28 publications

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“…4 insets). This is a general result for all armchair nanotubes 28 , for which the longitudinal optical (LO) phonon is not Raman-active due to symmetry 29,30 . REPs for all structures are shown in Fig.…”

Section: Resultsmentioning

confidence: 96%

“…Also, in these achiral nanotubes it is well established that the G-band Raman is composed of a single peak corresponding to the TO phonon mode (polarized along the nanotube circumferential direction) 7,28 . In fact, it has been shown that for these nanotubes the electron-phonon matrix elements for phonons polarized along the axial direction have negligible intensity 30 , and therefore, even if the phonon were to be polarized along an arbitrary direction along the nanotube surface, only the projection of the atomic displacements along the nanotube circumferential direction can contribute to the electron-phonon interaction. Therefore, the REPs for armchair nanotubes can be calculated unambiguously allowing for a direct comparison with experiments.…”

Section: Fig 6 Experimental (Red Dots) and Theoretical (Solid Lines)mentioning

confidence: 99%

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Asymmetric excitation profiles in the resonance Raman response of armchair carbon nanotubes

et al. 2015

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We performed tunable resonance Raman spectroscopy on samples highly enriched in the (5,5), (6,6), (7,7), and (8,8) armchair structures of metallic single-wall carbon nanotubes. We present Raman excitation profiles (REPs) for both the radial breathing mode and G-band phonons of these species. G-band excitation profiles are shown to resolve the expected incoming and outgoing resonances of the scattering process. Notably, the profiles are highly asymmetric, with the higherenergy outgoing resonance weaker than the incoming resonance. These results are comparable to the asymmetric excitation profiles observed previously in semiconducting nanotubes, introduce a new electronic type, and broaden the structural range over which the asymmetry is found to exist. Modeling of the behavior with a third-order quantum model that accounts for the k -dependence in energies and matrix elements, without including excitonic effects, is found to be insufficient for reproducing the observed asymmetry. We introduce an alternative fifth-order model in which the REP asymmetry arises from quantum interference introduced by phonon-mediated state-mixing between the E M 11 and K-momentum excitons. Such state-mixing effectively introduces a nuclear coordinate dependence in the transition dipole moment and thus may be viewed as a non-Condon effect from a molecular perspective. This result unifies a molecular-like picture of nanotube transitions (introduced by their excitonic nature) with a condensed matter approach for describing their behavior.

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Section: Resultsmentioning

confidence: 96%

Section: Fig 6 Experimental (Red Dots) and Theoretical (Solid Lines)mentioning

confidence: 99%

Asymmetric excitation profiles in the resonance Raman response of armchair carbon nanotubes

et al. 2015

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“…13,14 According to a very recent review, 15 chiral tubes have 14 Raman active vibrational modes which are distributed into 3A 1 C 5E 1 C 6E 2 species. For achiral tubes eight Raman active modes can be expected.…”

Section: Raman Scattering From Swcntsmentioning

confidence: 99%

Raman scattering from nanomaterials encapsulated into single wall carbon nanotubes

Kuzmany

Plank

Schaman

et al. 2007

J Raman Spectroscopy

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Raman scattering is used to study the filling of single wall carbon nanotubes with C 60 , C 59 N and anthracene. It is demonstrated how reversible opening and closing of the tubes can be used to check on the success of the filling process. In the case of C 59 N, filling was performed from the gas phase from 1 : 1 mixture between C 60 and C 59 N. Comparing the Raman spectra from the encapsulated mixture with the spectra from C 60 inside the tubes reveals that most of the molecules have reacted to form either the dimer (C 59 N) 2 or the hetero-dimer C 60 -C 59 N. Anthracene is demonstrated to enter the tubes but the molecule is subjected to a considerable geometrical change including some loss of hydrogens.

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“…In detail, the relation between nanotube diameters in real samples and the radial breathing mode spectrum is more complicated, because of the resonances in the Raman process and additional force constants coming from the tube-tube vander-Waals interaction in bundled nanotubes [3,5,6]. Furthermore, the RBM eigenvector has a small non-radial component [7,8].…”

mentioning

confidence: 99%

“…(2) [16]. The RBM eigenvector was obtained from finite differences; it has a small non-radial component [7,8] which lowers the calculated matrix elements by ≈ 30 %. All calculations were performed with the SIESTA code [17] within the local density approximation [18].…”

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confidence: 99%

The strength of the radial-breathing mode in single-walled carbon nanotubes

Machón

Reich

Telg

et al. 2004

AIP Conference Proceedings

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We show by ab initio calculations that the electron-phonon coupling matrix element M e-ph of the radial breathing mode in single-walled carbon nanotubes depends strongly on tube chirality. For nanotubes of the same diameter the coupling strength |M e-ph | 2 is up to one order of magnitude stronger for zig-zag than for armchair tubes. For (n1,n2) tubes M e-ph depends on the value of (n1 − n2) mod 3, which allows to discriminate semiconducting nanotubes with similar diameter by their Raman scattering intensity. We show measured resonance Raman profiles of the radial breathing mode which support our theoretical predictions.

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Single-wall carbon nanotubes phonon spectra: Symmetry-based calculations

Cited by 106 publications

References 28 publications

Asymmetric excitation profiles in the resonance Raman response of armchair carbon nanotubes

Asymmetric excitation profiles in the resonance Raman response of armchair carbon nanotubes

Raman scattering from nanomaterials encapsulated into single wall carbon nanotubes

The strength of the radial-breathing mode in single-walled carbon nanotubes

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