  The mechanical effects in finite two-dimensional electron systems (quantum
dots or droplets) in a strong perpendicular magnetic field are studied. It is
shown that, due to asymmetry of the cyclotron dynamics, an additional in-plane
electric field causes a ground state transition accompanied by a change in the
average total angular momentum of the system, unless the lateral confining
potential is exactly parabolic. A precise mechanical experiment is proposed in
which a macroscopic angular momentum of a dense matrix of quantum dots could be
measured and used to detect and estimate anharmonicity of the confinement.
