Exchange interaction effects in the thermodynamic properties of quantum dots

We study electron-electron interaction effects in the thermodynamic properties of quantum-dot systems. We obtain the direct and exchange contributions to the specific heat Cv in the self-consistent Hartree-Fock approximation at finite temperatures. An exchange-induced phase transition is observed and the transition temperature is shown to be inversely proportional to the size of the system. The exchange contribution to Cv dominates over the direct and kinetic contributions in the intermediate regime of interaction strength (rs∼1). Furthermore, the electron-electron interaction modifies both the amplitude and the period of magnetic field-induced oscillations in Cv