Magnetic-field-induced binding of few-electron systems in shallow quantum dots

Binding of few-electron systems in two-dimensional potential cavities in the presence of an external magnetic field is studied with the exact diagonalization approach. We demonstrate that the magnetic field leads to the formation of bound few-electron states which are unbound in the absence of the field. The critical value of the depth of the cavity allowing the formation of a bound state decreases with the magnetic field in a nonsmooth fashion due to the increasing angular momentum of the first bound state. In the high-magnetic-field limit the binding energies and the critical values for the depth of the potential cavity, allowing the formation of a bound system, tend to the classical values.