Electronic ground states of 3D electron gaz system in the quantum limit regime – QuantumLimit

The behavior of electrons in presence of a large magnetic field has always been at the heart of the understanding of the quantum matter. Recently, we discovered a cascade of electronic phase transitions induced by a strong magnetic field perpendicular to the graphene layers of bulk graphite. These phase transitions are believed to be driven by Coulomb interaction, which is expected to become significant among three-dimensional electrons confined to their lowest Landau levels. This so-called quantum limit has been extensively studied in the context of the quantum Hall effect in two dimensional electron gas systems and in single-layer graphene. However, little is known about the electronic organization in the three dimensional case. This is the topic of this proposal.

By combining several original probes, this project will provide a precise description of the field-induced states in graphite. It will also explore the universality of such instabilities in other dilute metals. A comparison between the rich physics of graphene and our measurements in graphite will clarify the fate of quantum Hall edge states when the interlayer coupling between independent graphene layers is increasing, i.e. as a third dimension is added to the two-dimensional electron gas. The project will thus reveal new states of the matter, possibly including a generalization of the 2D quantum Hall effect to the 3D case.