Contacts: Rebeca RIBEIRO-PALAU
Unraveling the fundamental nature of matter is one of the core challenges in solid-state physics. Different phases of matter are defined by their internal structure—known as orders. Among these, topological orders stand out for their remarkable robustness: they remain stable even under strong perturbations.
A well-known example is the quantum Hall effect (QHE). In this phenomenon, the topology of Landau levels gives rise to edge states that circulate along the boundaries of a two-dimensional electron gas. These edge channels suppress backscattering between charge carriers, enabling dissipationless transport. Remarkably, the quantized Hall resistance is unaffected by fabrication imperfections or material defects—highlighting the topological protection inherent in the band structure. Due to this exceptional stability, the QHE now serves as the global standard for electrical resistance in the International System of Units (SI).
Beyond the QHE, many other topologically protected states have been discovered, including the quantum spin Hall effect, topological insulators, and topological conductors. Understanding these exotic phases is a central focus of the TOPO2D research group.
To investigate these systems, TOPO2D employs van der Waals heterostructures, combining cutting-edge sample fabrication methods, precise layer alignment, and low-temperature electronic transport measurements. These tools allow us to probe, manipulate, and ultimately harness the unique properties of topological materials.
