The physics of quantum materials is dictated by many-body interactions and mathematical
concepts such as symmetry and topology that have transformed our understanding of matter …

Superconductivity is a remarkably widespread phenomenon that is observed in most metals
cooled to very low temperatures. The ubiquity of such conventional superconductors, and …

Superconductivity develops in metals upon the formation of a coherent macroscopic
quantum state of electron pairs. Iron pnictides and chalcogenides are materials that have …

Although the existence of nematic order in iron-based superconductors is now a well-
established experimental fact, its origin remains controversial. Nematic order breaks the …

Kamihara and coworkers' report of superconductivity at T c= 26 K in fluorine-doped
LaFeAsO inspired a worldwide effort to understand the nature of the superconductivity in this …

Since the discovery of high T c iron-based superconductors in early 2008, more than 15,000
papers have been published as a result of intensive research. This paper describes the …

The recently discovered Fe-pnictide and chalcogenide superconductors display low-
temperature properties suggesting superconducting gap structures which appear to vary …

The spontaneous reduction of rotational symmetry in a crystalline solid driven by an
electronic mechanism is referred to as electronic nematicity. This phenomenon—initially …

A fundamental and unconventional characteristic of superconductivity in iron-based
materials is that it occurs in the vicinity of two other instabilities. In addition to a tendency …

Four types of atomic-scale multipoles (electric, magnetic, magnetic toroidal, and electric
toroidal multipoles) give a complete set to describe arbitrary degrees of freedom for coupled …