• 文献标题:   Nonlinear optical conductivity resulting from the local energy spectrum at the M point in graphene
  • 文献类型:   Article
  • 作  者:   LIU Z, ZHANG C, CAO JC
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Univ Wollongong
  • 被引频次:   2
  • DOI:   10.1103/PhysRevB.96.035206
  • 出版年:   2017

▎ 摘  要

Based on the tight-binding model we construct a nonlinear Hamiltonian to describe the effective electric system around the M point for the single layer graphene. The local energy spectrum at the M point is approximated by the perfect hyperbolic geometry, and the modification by the screening effect from the substrate is taken into account. With the method based on the concept of the Floquet states and quasienergies (FSQ) we investigate the third order nonlinear conductivity sigma(3)(omega), sigma(3)(3 omega) for the different frequency ranges, respectively, in which only the pi - pi* bands are involved. A positive cusplike peak arises at h omega=epsilon(gap)(M)/3 for sigma(3)(3 omega) which originates from the three-photon processes. Also, there is a peak at epsilon(gap)(M)/2 for sigma(3)(omega) resulting from two-photon-resonant processes. The analysis of the pole processes indicates that a self-energy-like term transition process plays a role in the nonlinear optical response, and the different transition processes interact with each other during the response to the external field. These interactions can be influenced by the polarization of the external field.