High electron mobility transistor as electronic flute

We discuss the similarity between the plasma waves in two dimensional systems and sound waves. We show that the behavior of both types of waves is governed by the same equations. Therefore, we may create resonant structures for plasma waves, similar to those in musical instruments, and plasma waves can be excited by a DC current, just like wind musical instruments are excited by air jets. However, the plasma wave velocity (of the order of 10⁷ to 10⁸ cm/s) is much higher than the sound velocity, and the sizes of devices with the two dimensional electron gas are very small (of the order of a micrometer or less). Thus, the plasma wave frequencies are in the terahertz range, and the plasma waves can be coupled to far infrared electromagnetic radiation