The effect of a shearing electric field on molecular states of electrons in
quantum dots in strong magnetic fields is investigated theoretically. The
electron density in circularly symmetric dots is circularly symmetric but t
he pair correlation function has peaks whose positions have the same symmet
ry as the classical energy minimum. For small numbers of electrons this is
analogous to a rotating ring of electrons. The shearing electric field brea
ks the circular symmetry and stretches the ring, leading to states with lin
ear symmetry. This transition is found to have a strong effect on the addit
ion energy of a dot and can be either sudden or continuous, depending on th
e value of the magnetic field. It may be possible to use this effect as an
experimental probe of the physical nature of dot states. (C) 2001 Elsevier
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