Low-frequency noise in terahertz plasmonic field effect transistor sensors

Terahertz (THz) plasmonic field effect transistor sensors have emerged as prime contenders for applications in THz and sub-THz communications, biomedical sensing, and imaging. Noise is one of the most important factors determining their performance. We show that the conventional approach of using thermal noise of the device impedance for predicting the sensor performance is inadequate because it ignores the effect of the input circuit and (for very short, submicron devices) ignores a very strong effect of the ballistic or quasi-ballistic transport on the device performance.