On a basis of extensive analytical and numerical studies we show that a
linear-polarized microwave field creates a stationary magnetization in
mesoscopic ballistic quantum dots with two-dimensional electron gas being at a
thermal equilibrium. The magnetization is proportional to a number of electrons
in a dot and to a microwave power. Microwave fields of moderate strength create
in a one dot of few micron size a magnetization which is by few orders of
magnitude larger than a magnetization produced by persistent currents. The
effect is weakly dependent on temperature and can be observed with existing
experimental techniques. The parallels between this effect and ratchets in
asymmetric nanostructures are also discussed.Comment: 10 pages, 11 figs, research at http://www.quantware.ups-tlse.f