Quantum criticality in the iron pnictides and chalcogenides

TL;DR

This paper reviews the theoretical predictions and experimental evidence for quantum critical points in iron pnictides and chalcogenides, highlighting their potential role in superconductivity and the effects of isoelectronic substitution.

Contribution

It synthesizes theoretical models predicting magnetic quantum critical points and compiles experimental support in isoelectronically-tuned iron pnictides, advancing understanding of quantum criticality in these materials.

Findings

Evidence supports the existence of quantum critical points in isoelectronically-tuned iron pnictides.

Theoretical work predicts a magnetic quantum critical point from competition between localization and itinerancy.

Implications for superconductivity and material physics are discussed.

Abstract

Superconductivity in the iron pnictides and chalcogenides arises at the border of antiferromagnetism, which raises the question of the role of quantum criticality. In this topical review, we describe the theoretical work that led to the prediction for a magnetic quantum critical point arising out of a competition between electronic localization and itinerancy, and the proposal for accessing it by using isoelectronic P substitution for As in the undoped iron pnictides. We go on to compile the emerging experimental evidence in support of the existence of such a quantum critical point in isoelectronically-tuned iron pnictides. We close by discussing the implications of these results for the physics of the iron pnictides and chalcogenides.