Abstract-Strong tunable photomixing in semi-Dirac materials in the terahertz regime

                                                                   

Sunchao Huang, My Hanh Tran, Jack Zuber, Qian Wang, Yiming Zhu, and Chao Zhang

https://www.osapublishing.org/josab/abstract.cfm?uri=josab-36-2-200

We demonstrate a strong and anisotropic photomixing effect in an electronic system whose energy–momentum dispersion is parabolic in the 𝑥$$ direction and linear in the 𝑦$$ direction, such as a TiO2/VO2${}_{\mathrm{}}{}_{\mathrm{}}$ multilayered structure. The third-order photoresponses along the linear and parabolic directions have been analyzed and determined quantitatively. We have found a remarkable tunability of the mixing efficiency along the parabolic direction by a small electric field in the linear direction, up to two orders of magnitude. In the terahertz (THz) regime, the third-order response is comparable to the linear response under an applied field of 103–104  V/cm${\mathrm{}}^{\mathrm{}}{\mathrm{}}^{\mathrm{}}\mathrm{}$. Additionally, the nonlinear response persists at room temperature. The results may have applications where different current responses are required along different directions in the THz regime.

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