[17a-W9_326-1~12] 3.5 Ultrashort-pulse and high-intensity lasers

12:00 PM - 12:15 PM JST(3:00 AM - 3:15 AM UTC)

[17a-W9_326-12] Gradient-expansion analysis of nonlinear current response in graphene driven by Laguerre–Gaussian beams

〇Tamaya Tomohiro¹, Kenichi Ishikawa¹ (1.Univ. Tokyo)

Keywords:

graphene,LG beam

Laguerre–Gaussian (LG) beams carry orbital angular momentum characterized by the topological charge l and exhibit a spatially nonuniform phase/intensity profile. To describe OAM transfer to electrons, we formulate light–matter coupling in graphene using a systematic gradient expansion beyond the uniform-field (dipole) approximation. We compute time-dependent current components Jx(t) and Jy(t) at a local azimuthal angle phi and show that a transverse component Jy can be induced even under an x-polarized drive, reflecting locally broken inversion symmetry imposed by the structured field. Fourier analysis reveals l-dependent amplitudes and phases of harmonic components. We discuss how these spectral features vary with l and field strength.