Nonlinear Plasma Waves in Coupled Two-Dimensional Electron Systems

The two layers of two-dimensional electron gas (2DEG) systems are discussed in order to examine how the properties of developing nonlinear plasma waves are changed by the presence of electrostatic coupling between the two layers. We consider the case where the two layers are sandwiched by two metallic gates. If the separation between the 2DEG layers and gates is shorter than the wavelength of the investigating plasma waves, the Korteweg-de Vries (KdV) equation well characterizes their propagation. It is found that the velocity of the KdV solitons increases as the separation between two 2DEG layers becomes small; therefore, when the solitons couple with neighboring grating, they generate high-frequency Smith-Purcell radiations more effectively than the solitons supported by the single-layer system. [DOI: 10.1143/JJAP.47.8756]