  We study two-electron states confined in two coupled quantum dots formed by a
short-range potential in a two-dimensional topological insulator. It is shown
that there is a fairly wide range of the system parameters, where the ground
state is a tripletlike state formed by a superposition of two spin-polarized
states. Outside this range, the ground state is a singlet. A transition between
the singlet and triplet states can be realized by changing the potential of the
quantum dots. The effect is caused by a significant change in the energies of
the Coulomb repulsion and the exchange interaction of electrons due to the
presence of the pseudospin components of the wave function when the band
spectrum is inverted.
