NARROW-RESONANCE STATES OF 2D MAGNETIC SPIN-EXCITON IN PERIODICALLY MODULATED FIELDS

Two-dimensional electron gas (2DEG) under a strong perpendicular magne tic field in periodically modulated fields exhibits a peculiar discret e spectrum near the bottom of the spin-exciton band. The combined effe ct of the electrostatic modulation potential, and the e-h Coulomb attr action under the magnetic field, leads to nearly bound relative e-h os cillations perpendicular to the modulation axis, which ave a character istic Rydberg-like spectrum near the edge of the spin-exciton band. Th is low-lying, very narrow excitonic lines may significantly affect the spin and the charge transport in the thermally activated regime.