TY  - JOUR
AU  - Despoja, Vito
AU  - Radović, Ivan
AU  - Politano, Antonio
AU  - Mišković, Zoran L.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8953
AB  - The excitation spectrum in the region of the intraband (Dirac plasmon) and interband ( π plasmon) plasmons in graphene/Pt-skin terminated Pt 3 Ni(111) is reproduced by using an ab-initio method and an empirical model. The results of both methods are compared with experimental data. We discover that metallic screening by the Pt layer converts the square-root dispersion of the Dirac plasmon into a linear acoustic-like plasmon dispersion. In the long-wavelength limit, the Pt d electron excitations completely quench the π plasmon in graphene at about 4.1 eV, that is replaced by a broad peak at about 6 eV. Owing to a rather large graphene/Pt-skin separation (≈3.3 Å), the graphene/Pt-skin hybridization becomes weak at larger wave vectors, so that the π plasmon is recovered with a dispersion as in a free-standing graphene.
T2  - Nanomaterials
T1  - Insights on the Excitation Spectrum of Graphene Contacted with a Pt Skin
VL  - 10
IS  - 4
SP  - 703
DO  - 10.3390/nano10040703
ER  - 

@article{
author = "Despoja, Vito and Radović, Ivan and Politano, Antonio and Mišković, Zoran L.",
year = "2020",
abstract = "The excitation spectrum in the region of the intraband (Dirac plasmon) and interband ( π plasmon) plasmons in graphene/Pt-skin terminated Pt 3 Ni(111) is reproduced by using an ab-initio method and an empirical model. The results of both methods are compared with experimental data. We discover that metallic screening by the Pt layer converts the square-root dispersion of the Dirac plasmon into a linear acoustic-like plasmon dispersion. In the long-wavelength limit, the Pt d electron excitations completely quench the π plasmon in graphene at about 4.1 eV, that is replaced by a broad peak at about 6 eV. Owing to a rather large graphene/Pt-skin separation (≈3.3 Å), the graphene/Pt-skin hybridization becomes weak at larger wave vectors, so that the π plasmon is recovered with a dispersion as in a free-standing graphene.",
journal = "Nanomaterials",
title = "Insights on the Excitation Spectrum of Graphene Contacted with a Pt Skin",
volume = "10",
number = "4",
pages = "703",
doi = "10.3390/nano10040703"
}

Despoja, V., Radović, I., Politano, A.,& Mišković, Z. L.. (2020). Insights on the Excitation Spectrum of Graphene Contacted with a Pt Skin. in Nanomaterials, 10(4), 703.
https://doi.org/10.3390/nano10040703

Despoja V, Radović I, Politano A, Mišković ZL. Insights on the Excitation Spectrum of Graphene Contacted with a Pt Skin. in Nanomaterials. 2020;10(4):703.
doi:10.3390/nano10040703 .

Despoja, Vito, Radović, Ivan, Politano, Antonio, Mišković, Zoran L., "Insights on the Excitation Spectrum of Graphene Contacted with a Pt Skin" in Nanomaterials, 10, no. 4 (2020):703,
https://doi.org/10.3390/nano10040703 . .

TY  - JOUR
AU  - Politano, Antonio
AU  - Radović, Ivan
AU  - Borka, Duško
AU  - Mišković, Zoran L.
AU  - Yu, H. K.
AU  - Farias, D.
AU  - Chiarello, G.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1414
AB  - By means of angle-resolved electron energy loss spectroscopy, we have measured the interband it plasmon in high-quality graphene grown on peeled-off epitaxial Cu(111) foils. Experimental loss spectra have been reproduced by means of a hydrodynamic model. The dispersion relation of the plasmon frequency shows a nearly-flat dispersion up to a critical wave-vector of 0.3 angstrom(-1). We propose that the observed behavior could be originated by confinement effects in ripples in the strained graphene sheet. Strain also limits the dispersion at higher momenta, as a consequence of the increased effective mass of charge carriers. The analysis of momentum dependence of the line-width and of the inverse quality factor indicates that damping processes are dominated by decay in electron-hole pairs via indirect interband transitions. (C) 2016 Elsevier Ltd. All rights reserved.
T2  - Carbon
T1  - Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils
VL  - 114
SP  - 70
EP  - 76
DO  - 10.1016/j.carbon.2016.11.073
ER  - 

@article{
author = "Politano, Antonio and Radović, Ivan and Borka, Duško and Mišković, Zoran L. and Yu, H. K. and Farias, D. and Chiarello, G.",
year = "2017",
abstract = "By means of angle-resolved electron energy loss spectroscopy, we have measured the interband it plasmon in high-quality graphene grown on peeled-off epitaxial Cu(111) foils. Experimental loss spectra have been reproduced by means of a hydrodynamic model. The dispersion relation of the plasmon frequency shows a nearly-flat dispersion up to a critical wave-vector of 0.3 angstrom(-1). We propose that the observed behavior could be originated by confinement effects in ripples in the strained graphene sheet. Strain also limits the dispersion at higher momenta, as a consequence of the increased effective mass of charge carriers. The analysis of momentum dependence of the line-width and of the inverse quality factor indicates that damping processes are dominated by decay in electron-hole pairs via indirect interband transitions. (C) 2016 Elsevier Ltd. All rights reserved.",
journal = "Carbon",
title = "Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils",
volume = "114",
pages = "70-76",
doi = "10.1016/j.carbon.2016.11.073"
}

Politano, A., Radović, I., Borka, D., Mišković, Z. L., Yu, H. K., Farias, D.,& Chiarello, G.. (2017). Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils. in Carbon, 114, 70-76.
https://doi.org/10.1016/j.carbon.2016.11.073

Politano A, Radović I, Borka D, Mišković ZL, Yu HK, Farias D, Chiarello G. Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils. in Carbon. 2017;114:70-76.
doi:10.1016/j.carbon.2016.11.073 .

Politano, Antonio, Radović, Ivan, Borka, Duško, Mišković, Zoran L., Yu, H. K., Farias, D., Chiarello, G., "Dispersion and damping of the interband pi plasmon in graphene grown on Cu(111) foils" in Carbon, 114 (2017):70-76,
https://doi.org/10.1016/j.carbon.2016.11.073 . .

TY  - JOUR
AU  - Politano, Antonio
AU  - Radović, Ivan
AU  - Borka, Duško
AU  - Mišković, Zoran L.
AU  - Chiarello, G.
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/842
AB  - We present a theoretical modeling of the energy-loss spectroscopy data for monolayer graphene (MLG) supported by Pt(111), Ru(0001) and Ni(111) substrates. To reproduce the experimental loss function, we have used a two-dimensional, two-fluid hydrodynamic model for interband transitions of graphenes pi and sigma electrons and an empirical Drude-Lorentz model in the local approximation for metal substrates. The electronic response from the visible to the ultraviolet frequency range has been nicely reproduced for MLG/Pt(111) and MLG/Ru(0001). For graphene nanodomes on Ru(0001), the loss function of valleys shows an additional mode at 8-9 eV. By contrast, this models fails for the case of MLG/Ni(111), presumably due to the strong hybridization between the pi states of graphene and the d bands of Ni, which is not accounted for in the model. (C) 2015 Elsevier Ltd. All rights reserved.
T2  - Carbon
T1  - Interband plasmons in supported graphene on metal substrates: Theory and experiments
VL  - 96
SP  - 91
EP  - 97
DO  - 10.1016/j.carbon.2015.09.053
ER  - 

@article{
author = "Politano, Antonio and Radović, Ivan and Borka, Duško and Mišković, Zoran L. and Chiarello, G.",
year = "2016",
abstract = "We present a theoretical modeling of the energy-loss spectroscopy data for monolayer graphene (MLG) supported by Pt(111), Ru(0001) and Ni(111) substrates. To reproduce the experimental loss function, we have used a two-dimensional, two-fluid hydrodynamic model for interband transitions of graphenes pi and sigma electrons and an empirical Drude-Lorentz model in the local approximation for metal substrates. The electronic response from the visible to the ultraviolet frequency range has been nicely reproduced for MLG/Pt(111) and MLG/Ru(0001). For graphene nanodomes on Ru(0001), the loss function of valleys shows an additional mode at 8-9 eV. By contrast, this models fails for the case of MLG/Ni(111), presumably due to the strong hybridization between the pi states of graphene and the d bands of Ni, which is not accounted for in the model. (C) 2015 Elsevier Ltd. All rights reserved.",
journal = "Carbon",
title = "Interband plasmons in supported graphene on metal substrates: Theory and experiments",
volume = "96",
pages = "91-97",
doi = "10.1016/j.carbon.2015.09.053"
}

Politano, A., Radović, I., Borka, D., Mišković, Z. L.,& Chiarello, G.. (2016). Interband plasmons in supported graphene on metal substrates: Theory and experiments. in Carbon, 96, 91-97.
https://doi.org/10.1016/j.carbon.2015.09.053

Politano A, Radović I, Borka D, Mišković ZL, Chiarello G. Interband plasmons in supported graphene on metal substrates: Theory and experiments. in Carbon. 2016;96:91-97.
doi:10.1016/j.carbon.2015.09.053 .

Politano, Antonio, Radović, Ivan, Borka, Duško, Mišković, Zoran L., Chiarello, G., "Interband plasmons in supported graphene on metal substrates: Theory and experiments" in Carbon, 96 (2016):91-97,
https://doi.org/10.1016/j.carbon.2015.09.053 . .