Resonant transmission via magnetically bound states in periodic quantum structures

We study the magnetotransport properties of two typical periodic structures. It is found that the magnetic field has a dramatic impact on the resonant splittings via bound states in the structures. For an open periodic structure, the original (n-2)-fold resonant splitting rule at the beginning of the first conductance step is changed to (n-1)-fold splitting rule by magnetic modulation. The coupling effect of the edge states is very important to form the magnetically bound states corresponding to the n-1 resonant splitting peaks. For an electric superlattice consisting of n barriers, the magnetic modulation turns the n-1 low quasibound states into true bound states; thus, the lower-energy resonant splitting in conductance disappears. Instead, n-1 resonant peaks via magnetically bound states appear at the beginning of the first conductance step. The high states are mainly confined in the potential barriers rather than in the wells, and their wave functions in different regions are coupled together by the edge states. One can find the fingerprint of the edge states from the probability densities of the high states.