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arXiv · 1605.02837

Fermi energy dependence of first- and second-order Raman spectra in graphene: Kohn anomaly and quantum interference effect

Eddwi H. Hasdeo·Ahmad R. T. Nugraha·Mildred Dresselhaus·Riichiro Saito
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Abstract

Intensity of the first- and the second-order Raman spectra are calculated as a function of the Fermi energy. We show that the Kohn anomaly effect, i.e., phonon frequency renormalization, in the first-order Raman spectra originates from the phonon renormalization by the interband electron-hole excitation, whereas in the second-order Raman spectra, a competition between the interband and intraband electron-hole excitations takes place. By this calculation, we confirm the presence of different dispersive behaviors of the Raman peak frequency as a function of the Fermi energy for the first- and the second-order Raman spectra, as observed in experiments. Moreover, the calculated results of the Raman intensity sensitively depend on the Fermi energy for both the first- and the second-order Raman spectra. These results thus also show the importance of quantum interference effect phenomena.

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Eddwi H. Hasdeo, Ahmad R. T. Nugraha, Mildred Dresselhaus, Riichiro Saito. 2016-05-10. Fermi energy dependence of first- and second-order Raman spectra in graphene: Kohn anomaly and quantum interference effect. https://doi.org/10.1103/physrevb.94.075104

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