Theory of electric-field-controlled surface ferromagnetic transition in metals

It is widely believed that in metals, unlike in the dilute magnetic semiconductors, the control of ferromagnetic ordering by external voltage is hardly achievable. We compare the two types of ferromagnets and show that there is no obvious reason why metals are less preferable for this phenomenon. A similar effect in metals, however, has a different physical picture and should be identified as a voltage-induced surface transition. We study its properties within the theory of the surface critical phenomena and discuss possible difficulties on the way to its experimental realization.