Contacts: Rebeca RIBEIRO-PALAU
Understanding matter at its most fundamental level is one of the central goals of solid-state physics. Different phases of matter are distinguished by their internal structure, known as orders. A particularly remarkable class of these are topological orders, which are universal—they remain stable even under strong perturbations or disorder.
A quintessential example is the quantum Hall effect (QHE). In this phenomenon, the topological nature of Landau levels gives rise to chiral edge states that circulate along the boundaries of a two-dimensional electron gas. In these edge channels, backscattering is strongly suppressed, allowing charge carriers to flow without dissipation. The resulting quantization of Hall resistance is remarkably insensitive to imperfections such as defects or sample variability—reflecting the topological robustness of the system. Due to this stability, the QHE has been adopted worldwide as the standard for electrical resistance in the International System of Units (SI).
In this part of our research, we investigate the QHE in emerging materials, with a strong focus on graphene. Our interests span both fundamental questions—such as the competition between electron solid and liquid phases—and applied goals, including the development of graphene-based quantum Hall resistance standards for metrology.
In this part of our research we investigate the QHE in new materials such as graphene. Our interest of the QHE in graphene goes from the understanding of fundamental phenomena (e.g., elecron solid versus electron liquid states) to practical applications (e.g., graphene-based quantum Hall resistance standards).
