Nematic quantum criticality in an Fe-based superconductor revealed by strain-tuning

Pervasive criticality Iron-based superconductors are believed to host a quantum critical point (QCP), zero-temperature phase transition, beneath the “dome” delineating superconducting phase. Elucidating nature of this QCP is, however, tricky. Worasaran et al. set out do just that in prototypical iron-based superconductor, barium iron arsenide. By applying strain their samples, researchers found power-law behaviors characteristic nematic criticality. The associated fluctuations were present over large portion diagram. This method may be useful studying other material systems. Science , abb9280, issue p. 973