Symmetry-protected nodal phases in non-Hermitian systems

Symmetry plays a paramount role for the classification of phases of matter occurring in nature. Combining symmetry analysis with concepts from topology that allow us to identify global and robust physical properties, new phases of quantum matter, such as topological insulators and semimetals, have been discovered in recent years. Here, the authors analyze in general and exemplify the importance of symmetries to the dissipative counterparts of topological semimetals in non-Hermitian systems, thus introducing the notion of symmetry-protected non-Hermitian nodal phases.