Exact Theory of Edge Diffraction and Launching of Transverse Electric Plasmons at Two-Dimensional Junctions

An exact solution for electromagnetic wave diffraction at the junction of two-dimensional electron systems is obtained and analyzed for electric field polarized along the edge. A special emphasis is paid to the metal-contacted and terminated edges. In the former case, electric field at the edge tends to zero; in the latter case, it tends to a finite value which is screened by a two-dimensional system in an anomalous fashion. For both types of edge and capacitive type of the two-dimensional conductivity, an incident wave excites transverse electric two-dimensional plasmons. The amplitude of excited TE plasmons is maximized and becomes order of incident wave amplitude for capacitive impedance of two-dimensional electron systems order of free space impedance. For both large and small impedance of two-dimensional electron systems, the amplitude of TE plasmons tends to zero according to the power laws which are explicitly derived.