Resolving local lattice distortions in strongly correlated systems by total x-ray scattering*

Competing interactions in strongly correlated systems are known to lead to the emergence of collectively ordered electronic states such as unconventional superconductivity, charge density waves, complex magnetic order, nematic order, and Kondo lattice, to name a few. The orders appear intertwined in intricate phase diagrams and are often coupled to lattice degrees of freedom, including local lattice distortions. Local lattice distortions are, however, difficult to assess using traditional crystallographic techniques, rendering it difficult to quantify how they interact with the emerging orders. We will show that the problem can be resolved by employing non-standard experimental techniques such as total x-ray scattering coupled to 3D structure modeling. Examples will include results from our recent studies on UPt₂Si₂ [1] exhibiting Kondo lattice order and the charge density wave system 1T-TaS₂ [2].