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Using a combined two-dimensional-three-dimensional (2D-3D) ensemble Monte Carlo (EMC) model, the performance of a planar nanochannel device is studied at the terahertz (THz) region. The device is based on a GaN/AlGaN heterostructure in which a two-dimensional electron gas (2DEG) forms at the interface. Simulation results reveal that, at low working frequencies, the performance of the device is almost frequency independent. However, when the working frequency is higher than 0.5 THz, obvious enhancements in the device performance have been observed. The enhancements are characterized by two resonant peaks at frequencies of about 4 THz and 8 THz. Also, the frequency-dependent performance exhibits nonmonotonicity. Further studies show that the performance enhancements can be attributed to the excitations of 2D plasma waves in the device, with the emergence of the above resonant peaks corresponding to the formation of standing plasma waves. Moreover, simulation results show that the device performance increases monotonically with signal amplitude, when the device is unbiased. However, when a DC bias is applied, the performance remains almost unchanged for large signals but is significantly enhanced for small signals. Therefore, the device performance shows a strong nonmonotonic dependence on signal amplitude, and its minimal value occurs when the signal amplitude is only about2times the DC bias.

The influence of an optically induced waveguide lattice with a defect on the coherent interaction of one-dimensional lattice solitons (LSs) formed via the photovoltaic photorefractive effect is investigated by employing numerical simulations. The results show that the uniform lattice can keep the neighboring LSs propagating with constant spacing and can affect the energy transfer between them. Further research has shown that the energy transfer can be effectively controlled by adjusting the relative phase difference between neighboring LSs and by introducing a defect in the waveguide lattice.