Eur. Phys. J. D (2015) 69: 263
https://doi.org/10.1140/epjd/e2015-60233-2

Regular Article

Formation of infrared solitons in graphene ensemble under Raman excitation

¹ School of Physics and Electronics, Henan University, Kaifeng 475004, P.R. China
² School of Science, Hubei Province Key Laboratory of Intelligent Robot, Wuhan Institute of Technology, Wuhan 430073, P.R. China
³ Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
⁴ School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023, P.R. China

^a e-mail: clding2006@126.com

Received: 16 April 2015
Received in final form: 8 September 2015
Published online: 26 November 2015

Abstract

The formation of infrared solitons in graphene under Raman excitation is investigated using density-matrix approach. We find that the unique band structure and selection rules for the optical transitions near the Dirac point can result in extremely strong optical nonlinearity. Theoretical investigations with the aid of slowly varying envelope approximation and perturbation theory clearly indicate the existence of bright and dark solitons in Landau-quantized graphene. Actually, the formation of spatial soliton in such a material is the consequence of the balance between nonlinear effects and the dispersion properties. Also, the corresponding carrier frequency is tunable in the infrared range. These results can make us know better the crossover between optical solitons and graphene metamaterials. The predicted nonlinear optical effect in graphene may provide a new possibility for designing high-fidelity graphene-based information processing device.