Programme

P.16 -- Poster, VCTP-49

Date: Wednesday, 31 July 2024

Time: 08:30 - 10:00

Multiphoton absorption process of an intense electromagnetic waves in monolayer graphene under the influence of both uniform electric and magnetic fields

Nguyen Thu Huong (1), Nguyen Dinh Nam (2), Nguyen Quang Bau (2), Tran Anh Tuan (2)

(1) Academy of Air Defense and Air Force , Kim Son , Son Tay, Hanoi, Vietnam (2) Department of Theoretical Physics, Faculty of Physics, VNU University of Science, N0. 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam

In this paper, we present a comprehensive theoretical study of the influence of both uniform electric and magnetic fields on multi-photon absorption of intense electromagnetic waves (IEMW) in monolayer graphene (MLG) using the quantum kinetic equation. The electron-longitudinal optical phonon scattering mechanism is considered. Analytical expressions of the multiphoton absorption coefficient in MLG indicate a nonlinear dependence on many external parameters such as temperature, electric and magnetic field magnitudes as well as the photon energy and intensity of IEMW. We have numerically investigated the dependence of the resonance absorption spectrum as well as the Full width at half maximum (FWHM) on temperature, electric field and magnetic field. The results show that the position of resonance peaks in the absorption spectrum depends strongly on the Landau levels, electric sub-band levels, and electric field. However, temperature does not affect the position of the resonance peaks but only increases their intensity. Furthermore, the FWHM depends on the external field according to the square root law and has only a very small variation with temperature in the MLG. In particular, the external electric field increases the probability of electron-phonon scattering, causing a blue shift in the absorption spectrum and increasing FWHM. Our calculation results are in good agreement with previous theories and experiments in limited cases

Presenter: Nguyen Dinh Nam