Interference ionization of an impurity by an electric field in a system of quantum wells

A radical change in the ionization energy of the donor impurity Si in a GaAs/AlGaAs double-well heterostructure is observed experimentally when the electronic wave function is relocated in an electric field. The ionization energy of the impurity decreases from 15.5 meV to 0 when the voltage across the structure changes by less than 1 V. The Stark effect would give a change in the ionization energy of not more than 3 meV. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 3, 194–199 (10 February 1999)