Publication Details

Sun, J. D., Qin, H., Lewis, R. A., Yang, X. X., Sun, Y. F., Zhang, Z. P., Li, X. X., Zhang, X. Y., Cai, Y., Wu, D. M., Zhang, B. S. et al (2015). The effect of symmetry on resonant and nonresonant photoresponses in a field-effect terahertz detector. Applied Physics Letters, 106 (3), 031119-1-031119-5.


The effect of the symmetries in the terahertz (THz) field distribution and the field-effect channel on THz photoresponse is examined. Resonant excitation of cavity plasmon modes and nonresonant self-mixing of THz waves are demonstrated in a GaN/AlGaN two-dimensional electron gas with symmetrically designed nanogates, antennas, and filters. We found that the self-mixing signal can be effectively suppressed by the symmetric design and the resonant response benefits from the residual asymmetry. The findings suggest that a single detector may provide both high sensitivity from the self-mixing mechanism and spectral resolution from the resonant response by optimizing the degree of geometrical and/or electronic symmetries.



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