“Probing Electronic Nematicity in Iron-based Superconductors " By Johanna Palmstrom (Stanford University)

Wednesday, November 14, 2018 - 4:00pm to 5:00pm
Condensed Matter Physics Seminar


Underdoped iron-based superconductors undergo an electronic nematic ordering that accompanies or precedes an antiferromagnetic order and neighbors the superconducting dome. Consequently, in the disordered state iron-based superconductors are highly sensitive to perturbations of the same symmetry as the nematic order, such as antisymmetric (B2g) strain. In this work we use elastoresistivity measurements to explore the role electronic nematic fluctuations play in the normal state. We see that a divergent electronic nematic susceptibility is a universal feature of iron-based superconductors upon cooling towards the structural transition, and by also probing higher order responses we observe that nematic fluctuations play a significant role in determining the isotropic electronic response of these materials. Finally, I will describe a recent advancement in the elastoresistivity technique that has enabled measurements of the electronic nematic susceptibility in magnetic fields strong enough to suppress the superconducting dome.


PAB 4-330