Investigating the magneto-transport behavior of the potential topological semimetal MoTe₂

In the world of quantum physics, some of the most fascinating discoveries come from materials that behave in unexpected ways. One such class of materials is called Weyl semimetals. In these systems, electrons can act like massless particles known as Weyl fermions—something originally predicted in particle physics but never observed in nature. These materials are special because their electronic behavior is shaped not just by their structure or composition, but also by deeper mathematical properties known as topology.

In her thesis, Anna Carolina Marx Goncalves explores MoTe2, a layered crystal that changes its structure with temperature and is thought to shift between a regular electronic phase and a so-called topological phase. By studying how electric currents and magnetic fields interact with this material, Marx Goncalves gains insights into its unusual properties. For example, she observed electrical responses that shouldn’t exist without a magnetic field, and resistance that varies strongly with current direction—signatures that point toward the predicted topological nature of this material.

These experiments show that MoTe2 is more than just an interesting material—it’s a versatile platform for exploring new physics. Its layered nature, combined with its sensitivity to temperature and external fields, makes it ideal for probing complex quantum behavior. Even though we can't yet directly "see" these exotic electronic states, transport measurements give strong clues about what’s going on inside. In the future, this could lead to new kinds of electronics and sensors built on topological principles.

Dissertation: https://hdl.handle.net/11370/81073853-c94c-4aec-9e29-7c705d058ed2