Charge density waves in cuprate superconductors beyond thecritical doping
The unconventional normal-state properties of the cuprates are often discussed in terms of emergent electronic order that onsets below a putative critical doping of xc≈0.19. Charge density wave (CDW) correlations represent one such order; however, experimental evidence for such order generally spans a limited range of doping that falls short of the critical value xc, leading to questions regarding its essential relevance. Here, we use X-ray diffraction to demonstrate that CDW correlations in La2−xSrxCuO4 persist up to a doping of at least x=0.21. The correlations show strong changes through the superconducting transition, but no obvious discontinuity through xc≈0.19, despite changes in Fermi surface topology and electronic transport at this doping. These results demonstrate the interaction between CDWs and superconductivity even in overdoped cuprates and prompt are consideration of the role of CDW correlations in the high-temperature cuprate phase diagram.