Nodal-line semimetals and their variance

TL;DR

This review explores the classification, unique electronic structures, electromagnetic responses, and correlation effects in topological nodal-line semimetals, emphasizing their complex nodal configurations and potential for novel quantum phases.

Contribution

It provides a comprehensive classification of NLSMs based on nodal structures and symmetries, and discusses their electromagnetic properties and correlation effects.

Findings

NLSMs exhibit diverse nodal-line structures such as links, knots, and chains.

Electromagnetic responses include distinctive Landau levels and optical properties.

Strong correlations can induce novel quantum phases with intertwined magnetism and superconductivity.

Abstract

Topological nodal-line semimetals (NLSMs) are a new family of topological materials characterized by electronic band crossings that form lines in the Brillouin zone. These NLSMs host exotic nodal-line structures and exhibit distinct features such as drumhead surface states and unique electromagnetic responses. This review classifies various NLSM types based on their nodal structures and protecting symmetries, highlighting that these nodal-line structures can form links, knots, and chains. We discuss their characteristic electromagnetic responses, including Landau level spectroscopy, optical conductivity, and permittivity. Furthermore, the strong correlation effects in these NLSMs modify their semimetallic phases and lead to novel quantum phases where magnetism and superconductivity intertwine.