Conical diffraction in atomic vapor: Mathematical models and numerical calculations

Abstract

This study investigated the conical diffraction characteristics in the honeycomb lattice of a Λ-type three-level energy system for rubidium atomic configuration. Its band structure incorporates Dirac cones in accordance with the plane wave expansion method. We determined that the rotation angle θ of the three vectors strongly impacted the cone diffraction profile. For θ=0° and 60°, in the reciprocal lattice space, the Dirac cone states were excited, and symmetric cone diffraction was supported. When 0<θ<60°, an asymmetric cone diffraction with a dark notch appeared on the outer edge of the conical ring. The results indicate that the frequency detuning of the coupling field and high-order nonlinear susceptibilities in the medium are effective and concise approaches to manipulate the occurrence of cone diffraction. The findings of this study enhance the understanding of the cone diffraction phenomena and broaden the practical applicability of atomic configuration.