Atomic PDF analysis as a basis for calculating the electronic structure of quantum materials

TL;DR

This paper explores how atomic PDF analysis can improve understanding of quantum materials by linking structural distortions to electronic properties.

Contribution

The paper introduces the use of PDF analysis as a structural basis for computing electronic properties of quantum materials.

Findings

PDF analysis reveals structural distortions that affect electronic ground states in quantum materials.

Using PDF data with DFT improves predictions of electronic properties in materials like FeS and TaS2.

Examples include magnetoelectric, heavy fermion, and CDW systems.

Abstract

Competing interactions in quantum materials lead to the emergence of unusual electronic ground states, including unconventional superconductivity, charge density waves (CDWs), complex magnetic and nematic orders, and Kondo lattices, to name a few. The states are intertwined in intricate phase diagrams and coupled to lattice degrees of freedom that often appear as local structural distortions. There is mounting evidence that the distortions affect the ground states profoundly but are nontrivial to assess precisely using traditional crystallographic techniques, rendering it difficult to understand well why quantum materials behave one way or another.

Recently, atomic pair distribution function (PDF) analysis has proven very useful in studies of materials exhibit structural distortions. However, results from PDF analysis have rarely been used, if at all, as a structural basis for computing and/or predicting their electronic properties by density functional theory (DFT). In the talk, we will demonstrate the advantages of using PDF analysis as a basis for computing electronic properties of quantum materials exhibiting various degrees of structural distortions. Examples will include magnetoelectric FeS, dual heavy fermion APt2X2 intermetallics (A = U, Ce, or La and X = Si or Ge), NbTe4 CDW system (see Fig. 1) and Mott insulator 1-T TaS2 [1–4].