Spectroscopy of Natural and Artificial Atoms in Magnetic Fields

This chapter provides an overview of the action of magnetic fields on diluted media constituted by simple systems as natural atoms (such as neutral atoms, electrons, and ions) and artificial atoms with similar magnetic field response (such as semiconductor quantum dots and electron vacancies). In those media the interactions between the components of the medium play a limited role with respect to the magnetic energy of the components, while the very large precision achieved in spectroscopic measurements allows the determination of very tiny magnetic interactions. The precise quantum control of the interaction between a laser system and atoms is a key element of those measurements. Modification of atomic structures by the presence of magnetic fields has a very rich history dating back to the very birth of quantum mechanics. However, the motivations for studying those structures have also changed significantly as time progressed. The review covers latest findings and future prospects in a variety of magnetic property investigations, from the determination of atomic g-factors for relativistic correction and quantum-electrodynamics tests or of diamagnetic interactions, to the measurement of magnetic fields.