Evolution of electronic nematicity through the pseudogap phase in cuprate superconductors*

During the last decade, translational and rotational symmetry-breaking phases—density wave order and electronic nematicity—have been established as generic and distinct features of many correlated electron systems, including pnictide and cuprate superconductors. However, in cuprates, the relationship between these electronic symmetry-breaking phases and the enigmatic pseudogap phase remains unclear. Recently, we have employed resonant x-ray scattering in La-based cuprate high-temperature superconductors La_2-xM_xCuO₄ (M = Ba, Sr, Nd, Eu) to navigate the cuprate phase diagram, probing the relationship between electronic nematicity of the Cu 3d orbitals, charge order, and the pseudogap phase. The results established a clear link between electronic nematicity, the pseudogap, and its associated quantum critical point in overdoped cuprates. Here we will present the measurements extended to a wider doping range and to related compounds, La_2-x-yEu_ySr_xCuO4 and La_2-xBa_xCuO₄, to fully exploring the evolution of nematicity in the pseudogap phase.