Hosted by Brad Ramshaw

Feeling the Strain: Tuning the Critical Temperature of Electronic Nematic Phases

Quantum criticality associated with electronic nematic order has been suggested as a possible avenue for a range of exotic electronic effects, from non-Fermi liquid behavior to superconductivity. In order to study the behavior of metals proximate to such a quantum critical point, it is first necessary to establish effective tuning parameters that can drive the critical temperature of an electronic nematic phase to zero. In this talk I will describe how both symmetric and orthogonal antisymmetric strains can play this role, and demonstrate these effects in an archetypal Fe-based superconductor. For compositions progressively closer to the putative nematic quantum critical point, these tuning parameters become increasingly more effective, the precise variation of which provides direct evidence for a wide range of composition and temperature over which quantum critical fluctuations play a key role in shaping the properties of this family of materials. I will go on to introduce some other model material systems based on 4f ferroquadrupole order that offer some useful insights to these effects. If time allows I'll also briefly discuss an intimately related phenomenon, the elastocaloric effect, and explain why this is such a useful quantity to measure.

Poster