Study of edge magnetoplasma excitations in two-dimensional electron systems with various edge depletion profiles

Resonant microwave absorption by two-dimensional electrons has been measured using coplanar and strip methods. The influence of the edge of a two-dimensional system on the dispersion of edge magnetoplasmons has been studied. It has been found that the edge width can be varied within wide limits (by almost two orders of magnitude) by changing the etching depth of the crystal. It has been shown that the edge of the electron system in the case of etching through the quantum well has a width of about $0.2\mu$m, whereas the edge in the case of shallow etching (e.g., down to the donor layer) is smooth and can be as wide as $12\mu$m. The influence of a logarithmic factor, depending on the edge width of the electron system, on edge magnetoplasma excitations dispersion has been studied.