The dipole modes of non-parabolic quantum dots are studied by means of their
current and density patterns as well as with their local absorption
distribution. The anticrossing of the so-called Bernstein modes originates from
the coupling with electron-hole excitations of the two Landau bands which are
occupied at the corresponding magnetic fields. Non-quadratic terms in the
potential cause an energy separation between bulk and edge current modes in the
anticrossing region. On a local scale the fragmented peaks absorb energy in
complementary spatial regions which evolve with the magnetic field.Comment: 6 pages; embedded figs. 1-3; figs. 4, 5 separate files; accepted in
EPJ-