On the cutting edge: helical liquids in time-reversal-invariant topological materials

Abstract In this perspective, we discuss the unique electronic properties of helical liquids appearing at the boundaries of time-reversal-invariant topological materials and highlight the key challenges impeding progress in this field. We advocate for a deeper theoretical understanding of the many-body aspects of these systems to gain insights into helical liquids and the potential stabilization of topological zero modes. Such advancements are crucial for extensively exploring quantum phenomena and for the advancement of quantum science and engineering.