Charge-density-wave order takes over antiferromagnetism in Bi$_2$Sr$_{2-x}$La$_x$CuO$_{6}$ superconductors

Superconductivity appears in the cuprates when a spin order is destroyed, while the role of charge is less known. Recently, charge density wave (CDW) was found below the superconducting dome in YBa$_2$Cu$_3$O$_y$ when a high magnetic field is applied perpendicular to the CuO$_2$ plane, which was suggested to arise from incipient CDW in the vortex cores that becomes overlapped. Here, by $^{63}$Cu-nuclear magnetic resonance, we report the discovery of CDW induced by an in-plane field that does not create vortex cores in the plane, setting in above the dome in single-layered Bi$_2$Sr$_{2-x}$La$_x$CuO$_6$.The onset temperature $T_{\rm CDW}$ takes over the antiferromagnetic order temperature $T_{\rm N}$ beyond a critical doping level at which superconductivity starts to emerge, and scales with the psudogap temperature $T^{*}$. These results provide important insights into the relationship between spin order, CDW and the pseudogap, and their connections to high-temperature superconductivity.
Comment: 22 pages, 8 figures