Oblique modes effect on terahertz plasma wave resonant detection in InGaAs/InAlAs multichannel transistors

We report on the demonstration of narrow terahertz plasma wave resonant detection at low temperature in 200nm gate length InGaAs∕InAlAs multichannel high electron mobility transistors. We observe that the resonant detection linewidth is smaller than in full channel high electron mobility transistors. We interpret this shrinking by the effect of multichannel geometry that does not allow oblique plasma mode propagation along the channel.