  We study the influence of deformations on magnetic ordering in quantum dots
doped with magnetic impurities. The reduction of symmetry and the associated
deformation from circular to elliptical quantum confinement lead to the
formation of piezomagnetic quantum dots. The strength of elliptical deformation
can be controlled by the gate voltage to change the magnitude of magnetization,
at a fixed number of carriers and in the absence of applied magnetic field. We
reveal a reentrant magnetic ordering with the increase of elliptical
deformation and suggest that the piezomagnetic quantum dots can be used as
nanoscale magnetic switches.
