scholarly journals Tailoring plasmon excitations in $$\alpha -{\mathcal {T}}_3$$ armchair nanoribbons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrii Iurov ◽  
Liubov Zhemchuzhna ◽  
Godfrey Gumbs ◽  
Danhong Huang ◽  
Paula Fekete ◽  
...  

AbstractWe have calculated and investigated the electronic states, dynamical polarization function and the plasmon excitations for $$\alpha -{\mathcal {T}}_3$$ α - T 3 nanoribbons with armchair-edge termination. The obtained plasmon dispersions are found to depend significantly on the number of atomic rows across the ribbon and the energy gap which is also determined by the nanoribbon geometry. The bandgap appears to have the strongest effect on both the plasmon dispersions and their Landau damping. We have determined the conditions when relative hopping parameter $$\alpha $$ α of an $$\alpha -{\mathcal {T}}_3$$ α - T 3 lattice has a strong effect on the plasmons which makes our material distinguished from graphene nanoribbons. Our results for the electronic and collective properties of $$\alpha -{\mathcal {T}}_3$$ α - T 3 nanoribbons are expected to find numerous applications in the development of the next-generation electronic, nano-optical and plasmonic devices.

2021 ◽  
Author(s):  
Andrii Iurov ◽  
Liubov Zhemchuzhna ◽  
Godfrey Gumbs ◽  
Danhong Huang ◽  
Paula Fekete ◽  
...  

Abstract We have calculated and investigated the electronic states, dynamical polarization function and the plasmon excitations for α − T3 nanoribbons with armchair-edge termination. The obtained plasmon dispersions are found to depend significantly on the number of atomic rows across the ribbon and the energy gap which is also determined by the nanoribbon geometry. The bandgap appears to have the strongest effect on both the plasmon dispersions and their Landau damping. We have determined the conditions when relative hopping parameter α of an α − T3 lattice has a strong effect on the plasmons which makes our material distinguished from graphene nanoribbons. Our results for the electronic and collective properties of α − T3 nanoribbons are expected to find numerous applications in the development of the next-generation electronic, nano-optical and plasmonic devices.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
K. A. Dompreh ◽  
K. W. Adu ◽  
D. Sakyi-Arthur ◽  
N. G. Mensah ◽  
S. Y. Mensah ◽  
...  

AbstractWe perform self-consistent analysis of the Boltzmann transport equation for momentum and energy in the hypersound regime i.e., $$ql \gg 1$$ q l ≫ 1 ($$q$$ q is the acoustic wavenumber and l is the mean free path). We investigate the Landau damping of acoustic phonons ($$LDOAP$$ LDOAP ) in graphene nanoribbons, which leads to acoustoelectric current generation. Under a non-quantized field with drift velocity, we observed an acoustic phonon energy quantization that depends on the energy gap, the width, and the sub-index of the material. An effect similar to Cerenkov emission was observed, where the electron absorbed the confined acoustic phonon energy, causing the generation of acoustoelectric current in the graphene nanoribbon. A qualitative analysis of the dependence of the absorption coefficient and the acoustoelectric current on the phonon frequency is in agreement with experimental reports. We observed a shift in the peaks when the energy gap and the drift velocity were varied. Most importantly, a transparency window appears when the absorption coefficient is zero, making graphene nanoribbons a potential candidate for use as an acoustic wave filter with applications in tunable gate-controlled quantum information devices and phonon spectrometers.


2014 ◽  
Vol 1015 ◽  
pp. 155-158
Author(s):  
Wei Hua Wang ◽  
Cui Lan Zhao ◽  
Xin Jun Ma

The centre Au-doped armchair graphene nanoribbons (AGNRs) are investigated using the local density approximation based on density function theory. The charge density, electronic energy band and project density of states of centre Au-doped AGNRs are calculated. Our results indicate the charge density is transferred between C and Au atoms and mainly located on the Au atoms. The centre Au-doped AGNRs are an indirect band gap semiconductor with an energy gap of 1.046 eV. The Fermi level is located on valence band so that the AGNRs of doping Au become into degenerate semiconductor. The project density of states is calculated to reveal localization and hybridization between C-2pand Au-6s, 5delectronic states. The localization and hybridization are much stronger in the valence band. The hybridization between C-2pand Au-6pelectronic states are strongly in the conduction band.


Author(s):  
Jose Eduardo Barcelon ◽  
Marco Smerieri ◽  
Giovanni Carraro ◽  
Pawel Wojciechowski ◽  
Luca Vattuone ◽  
...  

Graphene nanoribbons (GNRs) are at the frontier of research on graphene materials since the 1D quantum confinement of electrons allows for the opening of an energy gap.


1997 ◽  
Vol 11 (11) ◽  
pp. 477-483 ◽  
Author(s):  
Z. J. Li ◽  
H. B. Xu ◽  
K. L. Yao

Starting from the extensional Su–Schrieffer–Heeger model taking into account the effects of interchain coupling, we have studied the energy spectra and electronic states of soliton excitation in polyacene. The dimerized displacement u0 is found to be similar to the case of trans-polyacetylene, and equals to 0.04 Å. The energy-band gap is 0.38 eV, in agreement with the results derived by other authors. Two new bound electronic states have been found in the conduction band and in the valence band, which is different from the one of trans-polyacetylene. There exists two degenerate soliton states in the center of energy gap. Furthermore, the distribution of charge density and spin density have been discussed in detail.


2018 ◽  
Vol 29 (31) ◽  
pp. 315705 ◽  
Author(s):  
Toyo Kazu Yamada ◽  
Hideto Fukuda ◽  
Taizo Fujiwara ◽  
Polin Liu ◽  
Kohji Nakamura ◽  
...  

Nanoscale ◽  
2018 ◽  
Vol 10 (31) ◽  
pp. 15003-15009 ◽  
Author(s):  
Asish Parbatani ◽  
Eui Sang Song ◽  
Fan Yang ◽  
Bin Yu

Low bulk band gaps and conductive surface electronic states of tetradymite topological insulators (TTI) make them potential candidates for next generation ultra-broadband photodevices.


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