In what magnetic field does an edge magnetoplasmon arise?

The behavior of magnetoplasmon modes in high-quality two-dimensional electron systems based on AlGaAs/GaAs heterostructures with a disk mesa is studied by the optical detection method for resonant microwave absorption. A magnetic field at which a two-dimensional skin layer is formed along the edge of a two-dimensional electron system and, as a result, the magnetoplasma mode becomes an edge mode has been determined by analyzing the magnetodispersion dependence. The dependence of this magnetic field on the two-dimensional electron density is studied. A model has been developed to describe the reported experimental results.