tailieunhanh - Investigation of Magneto-phonon Resonance in Graphene Monolayers
In this work, utilising the linear response theory we calculate the magneto conductivity (MC) in graphene monolayers, subjected to a static perpendicular magnetic field. The interaction of Dirac fermions with optical phonon via deformation potential is taken into account at high temperature. | VNU Journal of Science: Mathematics – Physics, Vol. 33, No. 4 (2017) 45-56 Investigation of Magneto-phonon Resonance in Graphene Monolayers Le Thi Thu Phuong1, Tran Thi My Duyen1, Vo Thanh Lam2, Bui Dinh Hoi1,* 1 University of Education, Hue University, Hue City, Vietnam 2 Sai Gon University, Ho Chi Minh City, Vietnam Received 11 October 2017 Revised 05 November 2017; Accepted 27 November 2017 Abstract: In this work, utilising the linear response theory we calculate the magneto conductivity (MC) in graphene monolayers, subjected to a static perpendicular magnetic field. The interaction of Dirac fermions with optical phonon via deformation potential is taken into account at high temperature. The dependence of the MC on the magnetic field shows resonant peaks that describe transitions of electrons between Landau levels via the resonant scattering with optical phonons. The effect of temperature on the MC is also obtained and discussed. Keywords: Magnetophonon resonance, graphene, optical phonon. 1. Introduction Magnetophonon resonance (MPR) arises from resonant phonon emission and absorption by electrons in semiconductors in high magnetic field [1-4]. The condition for the MPR has been obtained in bulk and conventional low-dimensional semiconductors as op M c , (1) where M = 1,2,3, , op and c are, respectively, the optical phonon and cyclotron frequency. MPR provides detailed information on carrier effective mass and phonon frequency at higher temperatures, typically between liquid nitrogen and room temperature. Since the first discovery [5], graphene has attracted numerous interest because of its unique properties that make graphene a promising candidate for future electronics devices. Electrons in graphene can move with a very high speed which leads to relativistic description of their dynamics, their behavior is described by the twodimensional Dirac equation for massless fermions. The energy dispersion in graphene is linear near the Dirac points. In .
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