Uniaxial strain tuning of the structural instabilities associate with the 1/8th anomaly in the high-Tc cuprates.

Competition exists in the high-Tc cuprates between the superconducting (SC), pseudogap and ordered charge density wave (CDW) states. A key doping level for understanding these competitions has been the 1/8 doping level, where an anomaly in the superconducting dome occurs (e.g., La2-xBaxCuO4), that is concomitant with a first order structural phase transition and is understood to supress 3d superconductivity. However, very recently we have shown that this structural phase transition does not run to completion, suggesting a natural explanation for the persistence of only 2D (in plane) SC at the 1/8 anomaly. Building on our recent theoretical predictions, we propose a single crystal in situ strain field experiment on WISH to tune the competition between these phases. Our results will provide a greater understanding of how the 3D superconducting state can be stabilised to higher temperatures in the high-Tc cuprates.