Orbital magnetic response of quantum dots: A signature of electron-electron interactions

We study the linear orbital magnetic response of quantum dots as a function of the number of electrons in the dot assuming a two-dimensional parabolic confining potential. We discuss the orientational paramagnetism and precession diamagnetism and show that each provides insights into the role of electron-electron interactions in the dot. We also study the response of three electrons in a strong magnetic field. Treating the Coulomb interaction as a perturbation, we find that the total angular momentum undergoes a continuous transition as a function of the magnetic-field strength, which results in the oscillations of electron-spin magnetization. We find no evidence that the interaction leads to spin polarization without the account of the Zeeman term.