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Nonlinear optical conductivity of two-dimensional semiconductors with Rashba spin-orbit coupling in terahertz regime
Australian Institute for Innovative Materials - Papers
  • Yee Sin Ang, University of Wollongong
  • J C Cao, Chinese Academy of Sciences
  • Chao Zhang, University of Wollongong
RIS ID
87495
Publication Date
1-1-2014
Publication Details

Ang, Y., Cao, J. C. & Zhang, C. (2014). Nonlinear optical conductivity of two-dimensional semiconductors with Rashba spin-orbit coupling in terahertz regime. European Physical Journal B: Condensed Matter and Complex Systems, 87 (28), 1-7.

Abstract

We reveal that two-dimensional semiconductors with Rashba spin-orbit interaction (R2DG) exhibit exceptionally strong nonlinear optical response (NOR) in the terahertz frequency regime. The spin-split of the parabolic energy band in R2DG allows strong multiple-photon process to occur via inter-subband mechanism. We show sharp multiple photon edges in the nonlinear conductivity. The edges correspond to the cut-off effect produced by the multiple-photon process. For Rashba coupling parameter of λ R ≈ 10−10 eV m, electric field strength in the order of only 102 V/cm is required for the NOR to dominate over the linear response. Furthermore, the roles of the parabolic ‘free electron’ term H 0 and the linear Rashba term H R on NOR of R2DG are also investigated. Although the NOR is made possible due to the presence of a finite H R , H 0 does play an important role on the NOR especially in high temperature regime. H 0 has rendered R2DG a strong optical nonlinearity at elevated temperature which is not found in a purely linear system such as graphene. The results suggest the possibilities of Rashba spintronic system in the application of nonlinear terahertz devices.

Grant Number
ARC/DP130102956
Citation Information
Yee Sin Ang, J C Cao and Chao Zhang. "Nonlinear optical conductivity of two-dimensional semiconductors with Rashba spin-orbit coupling in terahertz regime" (2014) p. 1 - 7
Available at: http://works.bepress.com/yee_sin_ang/13/