We analyse theoretically the possibilities of contactless control of in-gap
states formed by a pair of electrons confined in a triangular quantum ring. The
in-gap states are corner-localized states associated with two electrons
occupying the same corner area, and thus shifted to much higher energies than
other corner states, but still they are below the energies of
corner-side-localized states. We show how the energies, degeneracy and
splittings between consecutive levels change with the orientation of an
external electric field relatively to the polygonal cross section. We also show
how absorption changes in the presence of external electric and magnetic
fields.Comment: 4 pages, 2 figure