The eigenstates of electrons interacting in quantum dots in a magnetic field are studied. The interaction has important effects on the magnetic-field dependence of the energy spectrum. However, when the confinement potential is quadratic, the optical excitation energies of the many-body system are exactly the same as those of a single electron. This makes the interaction effects difficult to observe directly but they could be seen by measuring the thermodynamic properties of the electrons. This is illustrated with the calculations of the electronic heat capacity.

• Received 26 January 1990

DOI:https://doi.org/10.1103/PhysRevLett.65.108