Four-electron quantum dot molecule in a magnetic field

We have studied a two dimensional four-electron quantum dot molecule in a magnetic field using hyperspherical functions method. We calculate two lowest energy levels of the four-electron quantum dot molecule in a magnetic field. Our results show that the electron interactions are significant, as they can change the total spin of the four-electron ground state of the system by adjusting the magnetic field between $S$ = 0 and $S$ = 2. The energy difference between the lowest $S$ = 0 and $S$ = 2 states is shown as a function of the axial magnetic field. We found that the energy difference between the lowest $S$ = 0 and $S$ = 2 states in the strong-$B$ varies linearly. Our results should be important for constructing quantum gates and for studying strongly correlated quantum dot electronic states.